From 9e60eef04717555acfe11c8e6fff4c8b92b6537c Mon Sep 17 00:00:00 2001
From: Chris Pulman <chris.pulman@yahoo.com>
Date: Sun, 27 Jun 2021 23:47:53 +0100
Subject: [PATCH 1/2] test add tests for when any value (#2809)

* fix for WhenAnyValue now returns non nullable type

fix #2806
Remove nullable return value from WhenAnyValue

* Added WhenAnyValue Tests

Added tests to cover tuple and value return types
---
 ...provalTests.ReactiveUI.net472.approved.txt | 134 ++---
 ...provalTests.ReactiveUI.net5.0.approved.txt | 134 ++---
 ...ests.ReactiveUI.netcoreapp3.1.approved.txt | 134 ++---
 .../Activation/ActivatingViewFetcher.cs       |   2 +-
 .../Activation/ActivatingViewTests.cs         |   7 +-
 .../AutoPersist/AutoPersistHelperTest.cs      |   1 -
 .../Commands/CreatesCommandBindingTests.cs    |   3 -
 .../Commands/ReactiveCommandTest.cs           |   5 -
 .../Comparers/OrderedComparerTests.cs         |   3 +-
 .../InteractionBinderImplementationTests.cs   |   2 -
 .../Locator/DefaultViewLocatorTests.cs        |   3 -
 .../Mocks/CommandBindViewModel.cs             |   5 -
 .../Mocks/FakeCollectionModel.cs              |   6 -
 .../Mocks/FakeCollectionViewModel.cs          |   6 -
 .../Mocks/FakeNestedViewModel.cs              |   5 -
 src/ReactiveUI.Tests/Mocks/FakeViewModel.cs   |   5 -
 .../Mocks/PropertyBindModel.cs                |   6 -
 .../Mocks/PropertyBindViewModel.cs            |   5 -
 .../ObservableAsPropertyHelperTest.cs         |  22 +-
 .../ObservedChangedMixinTest.cs               |   5 +-
 .../windows-xaml/PropertyBindingTest.cs       |   4 +-
 .../WhenAnyThroughDependencyObjectTests.cs    |   6 +-
 .../Platforms/wpf/Mocks/CommandBindingView.cs |   5 -
 .../wpf/Mocks/CommandBindingViewModel.cs      |   5 -
 .../Platforms/wpf/Mocks/ExampleWindowView.cs  |   6 -
 .../wpf/Mocks/FakeXamlCommandBindingView.cs   |   3 -
 .../Platforms/wpf/Mocks/WpfTestUserControl.cs |   6 -
 .../WpfCommandBindingImplementationTests.cs   |   1 -
 .../wpf/WpfViewDependencyResolverTests.cs     |   4 -
 .../ReactiveObject/Mocks/AccountService.cs    |  48 ++
 .../ReactiveObject/Mocks/AccountUser.cs       |  32 ++
 .../Mocks/OaphNameOfTestFixture.cs            |   4 +-
 .../ReactiveObject/Mocks/Project.cs           |  32 ++
 .../ReactiveObject/Mocks/ProjectService.cs    |  51 ++
 .../Mocks/WhenAnyTestFixture.cs               | 198 +++++++
 .../Resolvers/DependencyResolverTests.cs      |   1 -
 .../PocoObservableForPropertyTests.cs         |   6 +-
 .../Routing/Mocks/TestScreen.cs               |   6 -
 .../Routing/Mocks/TestViewModel.cs            |   6 -
 .../Routing/RoutableViewModelMixinTests.cs    |  36 ++
 .../Routing/RoutingStateTests.cs              |  24 +-
 src/ReactiveUI.Tests/RxAppTest.cs             |   2 -
 .../SuspensionHostExtensionsTests.cs          |   6 +-
 .../Utilities/CompatMixins.cs                 |   2 -
 .../Utilities/CountingTestScheduler.cs        |   3 -
 .../Utilities/EnumerableTestMixin.cs          |   2 -
 src/ReactiveUI.Tests/Utilities/JsonHelper.cs  |   3 -
 src/ReactiveUI.Tests/Utilities/TestLogger.cs  |   3 -
 .../Utilities/UseInvariantCulture.cs          |   5 -
 .../ReactiveNotifyPropertyChangedMixinTest.cs | 486 ++++++++++++++++--
 .../ReactiveNotifyPropertyChangedMixin.cs     |   4 +-
 src/ReactiveUI/VariadicTemplates.cs           | 296 +++++------
 src/ReactiveUI/VariadicTemplates.tt           |  34 +-
 53 files changed, 1275 insertions(+), 548 deletions(-)
 create mode 100644 src/ReactiveUI.Tests/ReactiveObject/Mocks/AccountService.cs
 create mode 100644 src/ReactiveUI.Tests/ReactiveObject/Mocks/AccountUser.cs
 create mode 100644 src/ReactiveUI.Tests/ReactiveObject/Mocks/Project.cs
 create mode 100644 src/ReactiveUI.Tests/ReactiveObject/Mocks/ProjectService.cs
 create mode 100644 src/ReactiveUI.Tests/ReactiveObject/Mocks/WhenAnyTestFixture.cs

diff --git a/src/ReactiveUI.Tests/API/ApiApprovalTests.ReactiveUI.net472.approved.txt b/src/ReactiveUI.Tests/API/ApiApprovalTests.ReactiveUI.net472.approved.txt
index 73d37bb1aa..2672c89a07 100644
--- a/src/ReactiveUI.Tests/API/ApiApprovalTests.ReactiveUI.net472.approved.txt
+++ b/src/ReactiveUI.Tests/API/ApiApprovalTests.ReactiveUI.net472.approved.txt
@@ -608,7 +608,7 @@ namespace ReactiveUI
     }
     public static class ReactiveNotifyPropertyChangedMixin
     {
-        public static System.IObservable<ReactiveUI.IObservedChange<TSender, TValue?>> ObservableForProperty<TSender, TValue>(this TSender? item, System.Linq.Expressions.Expression<System.Func<TSender, TValue?>> property, bool beforeChange = false, bool skipInitial = true) { }
+        public static System.IObservable<ReactiveUI.IObservedChange<TSender, TValue>> ObservableForProperty<TSender, TValue>(this TSender? item, System.Linq.Expressions.Expression<System.Func<TSender, TValue?>> property, bool beforeChange = false, bool skipInitial = true) { }
         public static System.IObservable<TRet> ObservableForProperty<TSender, TValue, TRet>(this TSender? item, System.Linq.Expressions.Expression<System.Func<TSender, TValue?>> property, System.Func<TValue?, TRet> selector, bool beforeChange = false)
             where TSender :  class { }
         public static System.IObservable<ReactiveUI.IObservedChange<TSender, TValue>> SubscribeToExpressionChain<TSender, TValue>(this TSender? source, System.Linq.Expressions.Expression? expression, bool beforeChange = false, bool skipInitial = true, bool suppressWarnings = false) { }
@@ -835,97 +835,97 @@ namespace ReactiveUI
     }
     public static class WhenAnyMixin
     {
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1, T2>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, ReactiveUI.IObservedChange<TSender, T2?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1, T2, T3>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, ReactiveUI.IObservedChange<TSender, T2?>, ReactiveUI.IObservedChange<TSender, T3?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1, T2, T3, T4>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, ReactiveUI.IObservedChange<TSender, T2?>, ReactiveUI.IObservedChange<TSender, T3?>, ReactiveUI.IObservedChange<TSender, T4?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1, T2, T3, T4, T5>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, ReactiveUI.IObservedChange<TSender, T2?>, ReactiveUI.IObservedChange<TSender, T3?>, ReactiveUI.IObservedChange<TSender, T4?>, ReactiveUI.IObservedChange<TSender, T5?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, ReactiveUI.IObservedChange<TSender, T2?>, ReactiveUI.IObservedChange<TSender, T3?>, ReactiveUI.IObservedChange<TSender, T4?>, ReactiveUI.IObservedChange<TSender, T5?>, ReactiveUI.IObservedChange<TSender, T6?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, ReactiveUI.IObservedChange<TSender, T2?>, ReactiveUI.IObservedChange<TSender, T3?>, ReactiveUI.IObservedChange<TSender, T4?>, ReactiveUI.IObservedChange<TSender, T5?>, ReactiveUI.IObservedChange<TSender, T6?>, ReactiveUI.IObservedChange<TSender, T7?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, ReactiveUI.IObservedChange<TSender, T2?>, ReactiveUI.IObservedChange<TSender, T3?>, ReactiveUI.IObservedChange<TSender, T4?>, ReactiveUI.IObservedChange<TSender, T5?>, ReactiveUI.IObservedChange<TSender, T6?>, ReactiveUI.IObservedChange<TSender, T7?>, ReactiveUI.IObservedChange<TSender, T8?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, ReactiveUI.IObservedChange<TSender, T2?>, ReactiveUI.IObservedChange<TSender, T3?>, ReactiveUI.IObservedChange<TSender, T4?>, ReactiveUI.IObservedChange<TSender, T5?>, ReactiveUI.IObservedChange<TSender, T6?>, ReactiveUI.IObservedChange<TSender, T7?>, ReactiveUI.IObservedChange<TSender, T8?>, ReactiveUI.IObservedChange<TSender, T9?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, ReactiveUI.IObservedChange<TSender, T2?>, ReactiveUI.IObservedChange<TSender, T3?>, ReactiveUI.IObservedChange<TSender, T4?>, ReactiveUI.IObservedChange<TSender, T5?>, ReactiveUI.IObservedChange<TSender, T6?>, ReactiveUI.IObservedChange<TSender, T7?>, ReactiveUI.IObservedChange<TSender, T8?>, ReactiveUI.IObservedChange<TSender, T9?>, ReactiveUI.IObservedChange<TSender, T10?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Linq.Expressions.Expression<System.Func<TSender, T11?>> property11, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, ReactiveUI.IObservedChange<TSender, T2?>, ReactiveUI.IObservedChange<TSender, T3?>, ReactiveUI.IObservedChange<TSender, T4?>, ReactiveUI.IObservedChange<TSender, T5?>, ReactiveUI.IObservedChange<TSender, T6?>, ReactiveUI.IObservedChange<TSender, T7?>, ReactiveUI.IObservedChange<TSender, T8?>, ReactiveUI.IObservedChange<TSender, T9?>, ReactiveUI.IObservedChange<TSender, T10?>, ReactiveUI.IObservedChange<TSender, T11?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Linq.Expressions.Expression<System.Func<TSender, T11?>> property11, System.Linq.Expressions.Expression<System.Func<TSender, T12?>> property12, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, ReactiveUI.IObservedChange<TSender, T2?>, ReactiveUI.IObservedChange<TSender, T3?>, ReactiveUI.IObservedChange<TSender, T4?>, ReactiveUI.IObservedChange<TSender, T5?>, ReactiveUI.IObservedChange<TSender, T6?>, ReactiveUI.IObservedChange<TSender, T7?>, ReactiveUI.IObservedChange<TSender, T8?>, ReactiveUI.IObservedChange<TSender, T9?>, ReactiveUI.IObservedChange<TSender, T10?>, ReactiveUI.IObservedChange<TSender, T11?>, ReactiveUI.IObservedChange<TSender, T12?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Linq.Expressions.Expression? property8, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Linq.Expressions.Expression? property8, System.Linq.Expressions.Expression? property9, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Linq.Expressions.Expression? property8, System.Linq.Expressions.Expression? property9, System.Linq.Expressions.Expression? property10, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Linq.Expressions.Expression? property8, System.Linq.Expressions.Expression? property9, System.Linq.Expressions.Expression? property10, System.Linq.Expressions.Expression? property11, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Linq.Expressions.Expression? property8, System.Linq.Expressions.Expression? property9, System.Linq.Expressions.Expression? property10, System.Linq.Expressions.Expression? property11, System.Linq.Expressions.Expression? property12, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, TRet?>> property1) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Func<T1?, TRet> selector) { }
-        public static System.IObservable<System.ValueTuple<T1?, T2?>> WhenAnyValue<TSender, T1, T2>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1, T2>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Func<T1?, T2?, TRet> selector) { }
-        public static System.IObservable<System.ValueTuple<T1?, T2?, T3?>> WhenAnyValue<TSender, T1, T2, T3>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1, T2, T3>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Func<T1?, T2?, T3?, TRet> selector) { }
-        public static System.IObservable<System.ValueTuple<T1?, T2?, T3?, T4?>> WhenAnyValue<TSender, T1, T2, T3, T4>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1, T2, T3, T4>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Func<T1?, T2?, T3?, T4?, TRet> selector) { }
-        public static System.IObservable<System.ValueTuple<T1?, T2?, T3?, T4?, T5?>> WhenAnyValue<TSender, T1, T2, T3, T4, T5>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Func<T1?, T2?, T3?, T4?, T5?, TRet> selector) { }
-        public static System.IObservable<System.ValueTuple<T1?, T2?, T3?, T4?, T5?, T6?>> WhenAnyValue<TSender, T1, T2, T3, T4, T5, T6>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, TRet> selector) { }
-        public static System.IObservable<System.ValueTuple<T1?, T2?, T3?, T4?, T5?, T6?, T7?>> WhenAnyValue<TSender, T1, T2, T3, T4, T5, T6, T7>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, TRet> selector) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, TRet> selector) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, TRet> selector) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, TRet> selector) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Linq.Expressions.Expression<System.Func<TSender, T11?>> property11, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, T11?, TRet> selector) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Linq.Expressions.Expression<System.Func<TSender, T11?>> property11, System.Linq.Expressions.Expression<System.Func<TSender, T12?>> property12, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, T11?, T12?, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Func<ReactiveUI.IObservedChange<TSender, T1>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1, T2>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Func<ReactiveUI.IObservedChange<TSender, T1>, ReactiveUI.IObservedChange<TSender, T2>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1, T2, T3>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Func<ReactiveUI.IObservedChange<TSender, T1>, ReactiveUI.IObservedChange<TSender, T2>, ReactiveUI.IObservedChange<TSender, T3>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1, T2, T3, T4>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Func<ReactiveUI.IObservedChange<TSender, T1>, ReactiveUI.IObservedChange<TSender, T2>, ReactiveUI.IObservedChange<TSender, T3>, ReactiveUI.IObservedChange<TSender, T4>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1, T2, T3, T4, T5>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Func<ReactiveUI.IObservedChange<TSender, T1>, ReactiveUI.IObservedChange<TSender, T2>, ReactiveUI.IObservedChange<TSender, T3>, ReactiveUI.IObservedChange<TSender, T4>, ReactiveUI.IObservedChange<TSender, T5>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Func<ReactiveUI.IObservedChange<TSender, T1>, ReactiveUI.IObservedChange<TSender, T2>, ReactiveUI.IObservedChange<TSender, T3>, ReactiveUI.IObservedChange<TSender, T4>, ReactiveUI.IObservedChange<TSender, T5>, ReactiveUI.IObservedChange<TSender, T6>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Func<ReactiveUI.IObservedChange<TSender, T1>, ReactiveUI.IObservedChange<TSender, T2>, ReactiveUI.IObservedChange<TSender, T3>, ReactiveUI.IObservedChange<TSender, T4>, ReactiveUI.IObservedChange<TSender, T5>, ReactiveUI.IObservedChange<TSender, T6>, ReactiveUI.IObservedChange<TSender, T7>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Func<ReactiveUI.IObservedChange<TSender, T1>, ReactiveUI.IObservedChange<TSender, T2>, ReactiveUI.IObservedChange<TSender, T3>, ReactiveUI.IObservedChange<TSender, T4>, ReactiveUI.IObservedChange<TSender, T5>, ReactiveUI.IObservedChange<TSender, T6>, ReactiveUI.IObservedChange<TSender, T7>, ReactiveUI.IObservedChange<TSender, T8>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Func<ReactiveUI.IObservedChange<TSender, T1>, ReactiveUI.IObservedChange<TSender, T2>, ReactiveUI.IObservedChange<TSender, T3>, ReactiveUI.IObservedChange<TSender, T4>, ReactiveUI.IObservedChange<TSender, T5>, ReactiveUI.IObservedChange<TSender, T6>, ReactiveUI.IObservedChange<TSender, T7>, ReactiveUI.IObservedChange<TSender, T8>, ReactiveUI.IObservedChange<TSender, T9>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Func<ReactiveUI.IObservedChange<TSender, T1>, ReactiveUI.IObservedChange<TSender, T2>, ReactiveUI.IObservedChange<TSender, T3>, ReactiveUI.IObservedChange<TSender, T4>, ReactiveUI.IObservedChange<TSender, T5>, ReactiveUI.IObservedChange<TSender, T6>, ReactiveUI.IObservedChange<TSender, T7>, ReactiveUI.IObservedChange<TSender, T8>, ReactiveUI.IObservedChange<TSender, T9>, ReactiveUI.IObservedChange<TSender, T10>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Linq.Expressions.Expression<System.Func<TSender, T11?>> property11, System.Func<ReactiveUI.IObservedChange<TSender, T1>, ReactiveUI.IObservedChange<TSender, T2>, ReactiveUI.IObservedChange<TSender, T3>, ReactiveUI.IObservedChange<TSender, T4>, ReactiveUI.IObservedChange<TSender, T5>, ReactiveUI.IObservedChange<TSender, T6>, ReactiveUI.IObservedChange<TSender, T7>, ReactiveUI.IObservedChange<TSender, T8>, ReactiveUI.IObservedChange<TSender, T9>, ReactiveUI.IObservedChange<TSender, T10>, ReactiveUI.IObservedChange<TSender, T11>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Linq.Expressions.Expression<System.Func<TSender, T11?>> property11, System.Linq.Expressions.Expression<System.Func<TSender, T12?>> property12, System.Func<ReactiveUI.IObservedChange<TSender, T1>, ReactiveUI.IObservedChange<TSender, T2>, ReactiveUI.IObservedChange<TSender, T3>, ReactiveUI.IObservedChange<TSender, T4>, ReactiveUI.IObservedChange<TSender, T5>, ReactiveUI.IObservedChange<TSender, T6>, ReactiveUI.IObservedChange<TSender, T7>, ReactiveUI.IObservedChange<TSender, T8>, ReactiveUI.IObservedChange<TSender, T9>, ReactiveUI.IObservedChange<TSender, T10>, ReactiveUI.IObservedChange<TSender, T11>, ReactiveUI.IObservedChange<TSender, T12>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Linq.Expressions.Expression? property8, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Linq.Expressions.Expression? property8, System.Linq.Expressions.Expression? property9, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Linq.Expressions.Expression? property8, System.Linq.Expressions.Expression? property9, System.Linq.Expressions.Expression? property10, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Linq.Expressions.Expression? property8, System.Linq.Expressions.Expression? property9, System.Linq.Expressions.Expression? property10, System.Linq.Expressions.Expression? property11, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Linq.Expressions.Expression? property8, System.Linq.Expressions.Expression? property9, System.Linq.Expressions.Expression? property10, System.Linq.Expressions.Expression? property11, System.Linq.Expressions.Expression? property12, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, TRet?>> property1) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Func<T1, TRet> selector) { }
+        public static System.IObservable<System.ValueTuple<T1, T2>> WhenAnyValue<TSender, T1, T2>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1, T2>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Func<T1, T2, TRet> selector) { }
+        public static System.IObservable<System.ValueTuple<T1, T2, T3>> WhenAnyValue<TSender, T1, T2, T3>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1, T2, T3>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Func<T1, T2, T3, TRet> selector) { }
+        public static System.IObservable<System.ValueTuple<T1, T2, T3, T4>> WhenAnyValue<TSender, T1, T2, T3, T4>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1, T2, T3, T4>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Func<T1, T2, T3, T4, TRet> selector) { }
+        public static System.IObservable<System.ValueTuple<T1, T2, T3, T4, T5>> WhenAnyValue<TSender, T1, T2, T3, T4, T5>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Func<T1, T2, T3, T4, T5, TRet> selector) { }
+        public static System.IObservable<System.ValueTuple<T1, T2, T3, T4, T5, T6>> WhenAnyValue<TSender, T1, T2, T3, T4, T5, T6>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Func<T1, T2, T3, T4, T5, T6, TRet> selector) { }
+        public static System.IObservable<System.ValueTuple<T1, T2, T3, T4, T5, T6, T7>> WhenAnyValue<TSender, T1, T2, T3, T4, T5, T6, T7>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Func<T1, T2, T3, T4, T5, T6, T7, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Func<T1, T2, T3, T4, T5, T6, T7, T8, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Func<T1, T2, T3, T4, T5, T6, T7, T8, T9, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Func<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Linq.Expressions.Expression<System.Func<TSender, T11?>> property11, System.Func<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Linq.Expressions.Expression<System.Func<TSender, T11?>> property11, System.Linq.Expressions.Expression<System.Func<TSender, T12?>> property12, System.Func<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, TRet> selector) { }
     }
     public static class WhenAnyObservableMixin
     {
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs8)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs8)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs9)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs9)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs10)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs10)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs10, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs11)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs10, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs11)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs10, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs11, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs12)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs10, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs11, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs12)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1, T2>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Func<T1?, T2?, TRet?> selector)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet, T1, T2>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Func<T1?, T2?, TRet> selector)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1, T2, T3>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Func<T1?, T2?, T3?, TRet?> selector)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet, T1, T2, T3>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Func<T1?, T2?, T3?, TRet> selector)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Func<T1?, T2?, T3?, T4?, TRet?> selector)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Func<T1?, T2?, T3?, T4?, TRet> selector)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Func<T1?, T2?, T3?, T4?, T5?, TRet?> selector)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Func<T1?, T2?, T3?, T4?, T5?, TRet> selector)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, TRet?> selector)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, TRet> selector)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, TRet?> selector)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, TRet> selector)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T8>?>> obs8, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, TRet?> selector)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T8>?>> obs8, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, TRet> selector)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T8>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T9>?>> obs9, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, TRet?> selector)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T8>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T9>?>> obs9, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, TRet> selector)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T8>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T9>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T10>?>> obs10, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, TRet?> selector)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T8>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T9>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T10>?>> obs10, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, TRet> selector)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T8>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T9>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T10>?>> obs10, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T11>?>> obs11, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, T11?, TRet?> selector)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T8>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T9>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T10>?>> obs10, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T11>?>> obs11, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, T11?, TRet> selector)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T8>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T9>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T10>?>> obs10, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T11>?>> obs11, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T12>?>> obs12, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, T11?, T12?, TRet?> selector)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T8>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T9>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T10>?>> obs10, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T11>?>> obs11, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T12>?>> obs12, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, T11?, T12?, TRet> selector)
             where TSender :  class { }
     }
 }
diff --git a/src/ReactiveUI.Tests/API/ApiApprovalTests.ReactiveUI.net5.0.approved.txt b/src/ReactiveUI.Tests/API/ApiApprovalTests.ReactiveUI.net5.0.approved.txt
index 447e71d275..0c65c7eeed 100644
--- a/src/ReactiveUI.Tests/API/ApiApprovalTests.ReactiveUI.net5.0.approved.txt
+++ b/src/ReactiveUI.Tests/API/ApiApprovalTests.ReactiveUI.net5.0.approved.txt
@@ -603,7 +603,7 @@ namespace ReactiveUI
     }
     public static class ReactiveNotifyPropertyChangedMixin
     {
-        public static System.IObservable<ReactiveUI.IObservedChange<TSender, TValue?>> ObservableForProperty<TSender, TValue>(this TSender? item, System.Linq.Expressions.Expression<System.Func<TSender, TValue?>> property, bool beforeChange = false, bool skipInitial = true) { }
+        public static System.IObservable<ReactiveUI.IObservedChange<TSender, TValue>> ObservableForProperty<TSender, TValue>(this TSender? item, System.Linq.Expressions.Expression<System.Func<TSender, TValue?>> property, bool beforeChange = false, bool skipInitial = true) { }
         public static System.IObservable<TRet> ObservableForProperty<TSender, TValue, TRet>(this TSender? item, System.Linq.Expressions.Expression<System.Func<TSender, TValue?>> property, System.Func<TValue?, TRet> selector, bool beforeChange = false)
             where TSender :  class { }
         public static System.IObservable<ReactiveUI.IObservedChange<TSender, TValue>> SubscribeToExpressionChain<TSender, TValue>(this TSender? source, System.Linq.Expressions.Expression? expression, bool beforeChange = false, bool skipInitial = true, bool suppressWarnings = false) { }
@@ -830,97 +830,97 @@ namespace ReactiveUI
     }
     public static class WhenAnyMixin
     {
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1, T2>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, ReactiveUI.IObservedChange<TSender, T2?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1, T2, T3>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, ReactiveUI.IObservedChange<TSender, T2?>, ReactiveUI.IObservedChange<TSender, T3?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1, T2, T3, T4>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, ReactiveUI.IObservedChange<TSender, T2?>, ReactiveUI.IObservedChange<TSender, T3?>, ReactiveUI.IObservedChange<TSender, T4?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1, T2, T3, T4, T5>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, ReactiveUI.IObservedChange<TSender, T2?>, ReactiveUI.IObservedChange<TSender, T3?>, ReactiveUI.IObservedChange<TSender, T4?>, ReactiveUI.IObservedChange<TSender, T5?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, ReactiveUI.IObservedChange<TSender, T2?>, ReactiveUI.IObservedChange<TSender, T3?>, ReactiveUI.IObservedChange<TSender, T4?>, ReactiveUI.IObservedChange<TSender, T5?>, ReactiveUI.IObservedChange<TSender, T6?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, ReactiveUI.IObservedChange<TSender, T2?>, ReactiveUI.IObservedChange<TSender, T3?>, ReactiveUI.IObservedChange<TSender, T4?>, ReactiveUI.IObservedChange<TSender, T5?>, ReactiveUI.IObservedChange<TSender, T6?>, ReactiveUI.IObservedChange<TSender, T7?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, ReactiveUI.IObservedChange<TSender, T2?>, ReactiveUI.IObservedChange<TSender, T3?>, ReactiveUI.IObservedChange<TSender, T4?>, ReactiveUI.IObservedChange<TSender, T5?>, ReactiveUI.IObservedChange<TSender, T6?>, ReactiveUI.IObservedChange<TSender, T7?>, ReactiveUI.IObservedChange<TSender, T8?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, ReactiveUI.IObservedChange<TSender, T2?>, ReactiveUI.IObservedChange<TSender, T3?>, ReactiveUI.IObservedChange<TSender, T4?>, ReactiveUI.IObservedChange<TSender, T5?>, ReactiveUI.IObservedChange<TSender, T6?>, ReactiveUI.IObservedChange<TSender, T7?>, ReactiveUI.IObservedChange<TSender, T8?>, ReactiveUI.IObservedChange<TSender, T9?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, ReactiveUI.IObservedChange<TSender, T2?>, ReactiveUI.IObservedChange<TSender, T3?>, ReactiveUI.IObservedChange<TSender, T4?>, ReactiveUI.IObservedChange<TSender, T5?>, ReactiveUI.IObservedChange<TSender, T6?>, ReactiveUI.IObservedChange<TSender, T7?>, ReactiveUI.IObservedChange<TSender, T8?>, ReactiveUI.IObservedChange<TSender, T9?>, ReactiveUI.IObservedChange<TSender, T10?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Linq.Expressions.Expression<System.Func<TSender, T11?>> property11, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, ReactiveUI.IObservedChange<TSender, T2?>, ReactiveUI.IObservedChange<TSender, T3?>, ReactiveUI.IObservedChange<TSender, T4?>, ReactiveUI.IObservedChange<TSender, T5?>, ReactiveUI.IObservedChange<TSender, T6?>, ReactiveUI.IObservedChange<TSender, T7?>, ReactiveUI.IObservedChange<TSender, T8?>, ReactiveUI.IObservedChange<TSender, T9?>, ReactiveUI.IObservedChange<TSender, T10?>, ReactiveUI.IObservedChange<TSender, T11?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Linq.Expressions.Expression<System.Func<TSender, T11?>> property11, System.Linq.Expressions.Expression<System.Func<TSender, T12?>> property12, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, ReactiveUI.IObservedChange<TSender, T2?>, ReactiveUI.IObservedChange<TSender, T3?>, ReactiveUI.IObservedChange<TSender, T4?>, ReactiveUI.IObservedChange<TSender, T5?>, ReactiveUI.IObservedChange<TSender, T6?>, ReactiveUI.IObservedChange<TSender, T7?>, ReactiveUI.IObservedChange<TSender, T8?>, ReactiveUI.IObservedChange<TSender, T9?>, ReactiveUI.IObservedChange<TSender, T10?>, ReactiveUI.IObservedChange<TSender, T11?>, ReactiveUI.IObservedChange<TSender, T12?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Linq.Expressions.Expression? property8, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Linq.Expressions.Expression? property8, System.Linq.Expressions.Expression? property9, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Linq.Expressions.Expression? property8, System.Linq.Expressions.Expression? property9, System.Linq.Expressions.Expression? property10, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Linq.Expressions.Expression? property8, System.Linq.Expressions.Expression? property9, System.Linq.Expressions.Expression? property10, System.Linq.Expressions.Expression? property11, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Linq.Expressions.Expression? property8, System.Linq.Expressions.Expression? property9, System.Linq.Expressions.Expression? property10, System.Linq.Expressions.Expression? property11, System.Linq.Expressions.Expression? property12, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, TRet?>> property1) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Func<T1?, TRet> selector) { }
-        public static System.IObservable<System.ValueTuple<T1?, T2?>> WhenAnyValue<TSender, T1, T2>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1, T2>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Func<T1?, T2?, TRet> selector) { }
-        public static System.IObservable<System.ValueTuple<T1?, T2?, T3?>> WhenAnyValue<TSender, T1, T2, T3>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1, T2, T3>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Func<T1?, T2?, T3?, TRet> selector) { }
-        public static System.IObservable<System.ValueTuple<T1?, T2?, T3?, T4?>> WhenAnyValue<TSender, T1, T2, T3, T4>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1, T2, T3, T4>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Func<T1?, T2?, T3?, T4?, TRet> selector) { }
-        public static System.IObservable<System.ValueTuple<T1?, T2?, T3?, T4?, T5?>> WhenAnyValue<TSender, T1, T2, T3, T4, T5>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Func<T1?, T2?, T3?, T4?, T5?, TRet> selector) { }
-        public static System.IObservable<System.ValueTuple<T1?, T2?, T3?, T4?, T5?, T6?>> WhenAnyValue<TSender, T1, T2, T3, T4, T5, T6>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, TRet> selector) { }
-        public static System.IObservable<System.ValueTuple<T1?, T2?, T3?, T4?, T5?, T6?, T7?>> WhenAnyValue<TSender, T1, T2, T3, T4, T5, T6, T7>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, TRet> selector) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, TRet> selector) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, TRet> selector) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, TRet> selector) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Linq.Expressions.Expression<System.Func<TSender, T11?>> property11, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, T11?, TRet> selector) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Linq.Expressions.Expression<System.Func<TSender, T11?>> property11, System.Linq.Expressions.Expression<System.Func<TSender, T12?>> property12, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, T11?, T12?, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Func<ReactiveUI.IObservedChange<TSender, T1>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1, T2>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Func<ReactiveUI.IObservedChange<TSender, T1>, ReactiveUI.IObservedChange<TSender, T2>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1, T2, T3>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Func<ReactiveUI.IObservedChange<TSender, T1>, ReactiveUI.IObservedChange<TSender, T2>, ReactiveUI.IObservedChange<TSender, T3>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1, T2, T3, T4>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Func<ReactiveUI.IObservedChange<TSender, T1>, ReactiveUI.IObservedChange<TSender, T2>, ReactiveUI.IObservedChange<TSender, T3>, ReactiveUI.IObservedChange<TSender, T4>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1, T2, T3, T4, T5>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Func<ReactiveUI.IObservedChange<TSender, T1>, ReactiveUI.IObservedChange<TSender, T2>, ReactiveUI.IObservedChange<TSender, T3>, ReactiveUI.IObservedChange<TSender, T4>, ReactiveUI.IObservedChange<TSender, T5>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Func<ReactiveUI.IObservedChange<TSender, T1>, ReactiveUI.IObservedChange<TSender, T2>, ReactiveUI.IObservedChange<TSender, T3>, ReactiveUI.IObservedChange<TSender, T4>, ReactiveUI.IObservedChange<TSender, T5>, ReactiveUI.IObservedChange<TSender, T6>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Func<ReactiveUI.IObservedChange<TSender, T1>, ReactiveUI.IObservedChange<TSender, T2>, ReactiveUI.IObservedChange<TSender, T3>, ReactiveUI.IObservedChange<TSender, T4>, ReactiveUI.IObservedChange<TSender, T5>, ReactiveUI.IObservedChange<TSender, T6>, ReactiveUI.IObservedChange<TSender, T7>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Func<ReactiveUI.IObservedChange<TSender, T1>, ReactiveUI.IObservedChange<TSender, T2>, ReactiveUI.IObservedChange<TSender, T3>, ReactiveUI.IObservedChange<TSender, T4>, ReactiveUI.IObservedChange<TSender, T5>, ReactiveUI.IObservedChange<TSender, T6>, ReactiveUI.IObservedChange<TSender, T7>, ReactiveUI.IObservedChange<TSender, T8>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Func<ReactiveUI.IObservedChange<TSender, T1>, ReactiveUI.IObservedChange<TSender, T2>, ReactiveUI.IObservedChange<TSender, T3>, ReactiveUI.IObservedChange<TSender, T4>, ReactiveUI.IObservedChange<TSender, T5>, ReactiveUI.IObservedChange<TSender, T6>, ReactiveUI.IObservedChange<TSender, T7>, ReactiveUI.IObservedChange<TSender, T8>, ReactiveUI.IObservedChange<TSender, T9>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Func<ReactiveUI.IObservedChange<TSender, T1>, ReactiveUI.IObservedChange<TSender, T2>, ReactiveUI.IObservedChange<TSender, T3>, ReactiveUI.IObservedChange<TSender, T4>, ReactiveUI.IObservedChange<TSender, T5>, ReactiveUI.IObservedChange<TSender, T6>, ReactiveUI.IObservedChange<TSender, T7>, ReactiveUI.IObservedChange<TSender, T8>, ReactiveUI.IObservedChange<TSender, T9>, ReactiveUI.IObservedChange<TSender, T10>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Linq.Expressions.Expression<System.Func<TSender, T11?>> property11, System.Func<ReactiveUI.IObservedChange<TSender, T1>, ReactiveUI.IObservedChange<TSender, T2>, ReactiveUI.IObservedChange<TSender, T3>, ReactiveUI.IObservedChange<TSender, T4>, ReactiveUI.IObservedChange<TSender, T5>, ReactiveUI.IObservedChange<TSender, T6>, ReactiveUI.IObservedChange<TSender, T7>, ReactiveUI.IObservedChange<TSender, T8>, ReactiveUI.IObservedChange<TSender, T9>, ReactiveUI.IObservedChange<TSender, T10>, ReactiveUI.IObservedChange<TSender, T11>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Linq.Expressions.Expression<System.Func<TSender, T11?>> property11, System.Linq.Expressions.Expression<System.Func<TSender, T12?>> property12, System.Func<ReactiveUI.IObservedChange<TSender, T1>, ReactiveUI.IObservedChange<TSender, T2>, ReactiveUI.IObservedChange<TSender, T3>, ReactiveUI.IObservedChange<TSender, T4>, ReactiveUI.IObservedChange<TSender, T5>, ReactiveUI.IObservedChange<TSender, T6>, ReactiveUI.IObservedChange<TSender, T7>, ReactiveUI.IObservedChange<TSender, T8>, ReactiveUI.IObservedChange<TSender, T9>, ReactiveUI.IObservedChange<TSender, T10>, ReactiveUI.IObservedChange<TSender, T11>, ReactiveUI.IObservedChange<TSender, T12>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Linq.Expressions.Expression? property8, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Linq.Expressions.Expression? property8, System.Linq.Expressions.Expression? property9, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Linq.Expressions.Expression? property8, System.Linq.Expressions.Expression? property9, System.Linq.Expressions.Expression? property10, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Linq.Expressions.Expression? property8, System.Linq.Expressions.Expression? property9, System.Linq.Expressions.Expression? property10, System.Linq.Expressions.Expression? property11, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Linq.Expressions.Expression? property8, System.Linq.Expressions.Expression? property9, System.Linq.Expressions.Expression? property10, System.Linq.Expressions.Expression? property11, System.Linq.Expressions.Expression? property12, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, TRet?>> property1) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Func<T1, TRet> selector) { }
+        public static System.IObservable<System.ValueTuple<T1, T2>> WhenAnyValue<TSender, T1, T2>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1, T2>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Func<T1, T2, TRet> selector) { }
+        public static System.IObservable<System.ValueTuple<T1, T2, T3>> WhenAnyValue<TSender, T1, T2, T3>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1, T2, T3>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Func<T1, T2, T3, TRet> selector) { }
+        public static System.IObservable<System.ValueTuple<T1, T2, T3, T4>> WhenAnyValue<TSender, T1, T2, T3, T4>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1, T2, T3, T4>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Func<T1, T2, T3, T4, TRet> selector) { }
+        public static System.IObservable<System.ValueTuple<T1, T2, T3, T4, T5>> WhenAnyValue<TSender, T1, T2, T3, T4, T5>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Func<T1, T2, T3, T4, T5, TRet> selector) { }
+        public static System.IObservable<System.ValueTuple<T1, T2, T3, T4, T5, T6>> WhenAnyValue<TSender, T1, T2, T3, T4, T5, T6>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Func<T1, T2, T3, T4, T5, T6, TRet> selector) { }
+        public static System.IObservable<System.ValueTuple<T1, T2, T3, T4, T5, T6, T7>> WhenAnyValue<TSender, T1, T2, T3, T4, T5, T6, T7>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Func<T1, T2, T3, T4, T5, T6, T7, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Func<T1, T2, T3, T4, T5, T6, T7, T8, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Func<T1, T2, T3, T4, T5, T6, T7, T8, T9, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Func<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Linq.Expressions.Expression<System.Func<TSender, T11?>> property11, System.Func<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Linq.Expressions.Expression<System.Func<TSender, T11?>> property11, System.Linq.Expressions.Expression<System.Func<TSender, T12?>> property12, System.Func<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, TRet> selector) { }
     }
     public static class WhenAnyObservableMixin
     {
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs8)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs8)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs9)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs9)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs10)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs10)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs10, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs11)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs10, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs11)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs10, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs11, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs12)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs10, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs11, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs12)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1, T2>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Func<T1?, T2?, TRet?> selector)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet, T1, T2>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Func<T1?, T2?, TRet> selector)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1, T2, T3>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Func<T1?, T2?, T3?, TRet?> selector)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet, T1, T2, T3>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Func<T1?, T2?, T3?, TRet> selector)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Func<T1?, T2?, T3?, T4?, TRet?> selector)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Func<T1?, T2?, T3?, T4?, TRet> selector)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Func<T1?, T2?, T3?, T4?, T5?, TRet?> selector)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Func<T1?, T2?, T3?, T4?, T5?, TRet> selector)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, TRet?> selector)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, TRet> selector)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, TRet?> selector)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, TRet> selector)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T8>?>> obs8, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, TRet?> selector)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T8>?>> obs8, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, TRet> selector)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T8>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T9>?>> obs9, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, TRet?> selector)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T8>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T9>?>> obs9, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, TRet> selector)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T8>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T9>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T10>?>> obs10, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, TRet?> selector)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T8>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T9>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T10>?>> obs10, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, TRet> selector)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T8>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T9>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T10>?>> obs10, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T11>?>> obs11, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, T11?, TRet?> selector)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T8>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T9>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T10>?>> obs10, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T11>?>> obs11, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, T11?, TRet> selector)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T8>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T9>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T10>?>> obs10, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T11>?>> obs11, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T12>?>> obs12, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, T11?, T12?, TRet?> selector)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T8>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T9>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T10>?>> obs10, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T11>?>> obs11, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T12>?>> obs12, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, T11?, T12?, TRet> selector)
             where TSender :  class { }
     }
 }
diff --git a/src/ReactiveUI.Tests/API/ApiApprovalTests.ReactiveUI.netcoreapp3.1.approved.txt b/src/ReactiveUI.Tests/API/ApiApprovalTests.ReactiveUI.netcoreapp3.1.approved.txt
index 9e24a24957..cc29c22122 100644
--- a/src/ReactiveUI.Tests/API/ApiApprovalTests.ReactiveUI.netcoreapp3.1.approved.txt
+++ b/src/ReactiveUI.Tests/API/ApiApprovalTests.ReactiveUI.netcoreapp3.1.approved.txt
@@ -601,7 +601,7 @@ namespace ReactiveUI
     }
     public static class ReactiveNotifyPropertyChangedMixin
     {
-        public static System.IObservable<ReactiveUI.IObservedChange<TSender, TValue?>> ObservableForProperty<TSender, TValue>(this TSender? item, System.Linq.Expressions.Expression<System.Func<TSender, TValue?>> property, bool beforeChange = false, bool skipInitial = true) { }
+        public static System.IObservable<ReactiveUI.IObservedChange<TSender, TValue>> ObservableForProperty<TSender, TValue>(this TSender? item, System.Linq.Expressions.Expression<System.Func<TSender, TValue?>> property, bool beforeChange = false, bool skipInitial = true) { }
         public static System.IObservable<TRet> ObservableForProperty<TSender, TValue, TRet>(this TSender? item, System.Linq.Expressions.Expression<System.Func<TSender, TValue?>> property, System.Func<TValue?, TRet> selector, bool beforeChange = false)
             where TSender :  class { }
         public static System.IObservable<ReactiveUI.IObservedChange<TSender, TValue>> SubscribeToExpressionChain<TSender, TValue>(this TSender? source, System.Linq.Expressions.Expression? expression, bool beforeChange = false, bool skipInitial = true, bool suppressWarnings = false) { }
@@ -828,97 +828,97 @@ namespace ReactiveUI
     }
     public static class WhenAnyMixin
     {
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1, T2>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, ReactiveUI.IObservedChange<TSender, T2?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1, T2, T3>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, ReactiveUI.IObservedChange<TSender, T2?>, ReactiveUI.IObservedChange<TSender, T3?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1, T2, T3, T4>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, ReactiveUI.IObservedChange<TSender, T2?>, ReactiveUI.IObservedChange<TSender, T3?>, ReactiveUI.IObservedChange<TSender, T4?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1, T2, T3, T4, T5>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, ReactiveUI.IObservedChange<TSender, T2?>, ReactiveUI.IObservedChange<TSender, T3?>, ReactiveUI.IObservedChange<TSender, T4?>, ReactiveUI.IObservedChange<TSender, T5?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, ReactiveUI.IObservedChange<TSender, T2?>, ReactiveUI.IObservedChange<TSender, T3?>, ReactiveUI.IObservedChange<TSender, T4?>, ReactiveUI.IObservedChange<TSender, T5?>, ReactiveUI.IObservedChange<TSender, T6?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, ReactiveUI.IObservedChange<TSender, T2?>, ReactiveUI.IObservedChange<TSender, T3?>, ReactiveUI.IObservedChange<TSender, T4?>, ReactiveUI.IObservedChange<TSender, T5?>, ReactiveUI.IObservedChange<TSender, T6?>, ReactiveUI.IObservedChange<TSender, T7?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, ReactiveUI.IObservedChange<TSender, T2?>, ReactiveUI.IObservedChange<TSender, T3?>, ReactiveUI.IObservedChange<TSender, T4?>, ReactiveUI.IObservedChange<TSender, T5?>, ReactiveUI.IObservedChange<TSender, T6?>, ReactiveUI.IObservedChange<TSender, T7?>, ReactiveUI.IObservedChange<TSender, T8?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, ReactiveUI.IObservedChange<TSender, T2?>, ReactiveUI.IObservedChange<TSender, T3?>, ReactiveUI.IObservedChange<TSender, T4?>, ReactiveUI.IObservedChange<TSender, T5?>, ReactiveUI.IObservedChange<TSender, T6?>, ReactiveUI.IObservedChange<TSender, T7?>, ReactiveUI.IObservedChange<TSender, T8?>, ReactiveUI.IObservedChange<TSender, T9?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, ReactiveUI.IObservedChange<TSender, T2?>, ReactiveUI.IObservedChange<TSender, T3?>, ReactiveUI.IObservedChange<TSender, T4?>, ReactiveUI.IObservedChange<TSender, T5?>, ReactiveUI.IObservedChange<TSender, T6?>, ReactiveUI.IObservedChange<TSender, T7?>, ReactiveUI.IObservedChange<TSender, T8?>, ReactiveUI.IObservedChange<TSender, T9?>, ReactiveUI.IObservedChange<TSender, T10?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Linq.Expressions.Expression<System.Func<TSender, T11?>> property11, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, ReactiveUI.IObservedChange<TSender, T2?>, ReactiveUI.IObservedChange<TSender, T3?>, ReactiveUI.IObservedChange<TSender, T4?>, ReactiveUI.IObservedChange<TSender, T5?>, ReactiveUI.IObservedChange<TSender, T6?>, ReactiveUI.IObservedChange<TSender, T7?>, ReactiveUI.IObservedChange<TSender, T8?>, ReactiveUI.IObservedChange<TSender, T9?>, ReactiveUI.IObservedChange<TSender, T10?>, ReactiveUI.IObservedChange<TSender, T11?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Linq.Expressions.Expression<System.Func<TSender, T11?>> property11, System.Linq.Expressions.Expression<System.Func<TSender, T12?>> property12, System.Func<ReactiveUI.IObservedChange<TSender, T1?>, ReactiveUI.IObservedChange<TSender, T2?>, ReactiveUI.IObservedChange<TSender, T3?>, ReactiveUI.IObservedChange<TSender, T4?>, ReactiveUI.IObservedChange<TSender, T5?>, ReactiveUI.IObservedChange<TSender, T6?>, ReactiveUI.IObservedChange<TSender, T7?>, ReactiveUI.IObservedChange<TSender, T8?>, ReactiveUI.IObservedChange<TSender, T9?>, ReactiveUI.IObservedChange<TSender, T10?>, ReactiveUI.IObservedChange<TSender, T11?>, ReactiveUI.IObservedChange<TSender, T12?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Linq.Expressions.Expression? property8, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Linq.Expressions.Expression? property8, System.Linq.Expressions.Expression? property9, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Linq.Expressions.Expression? property8, System.Linq.Expressions.Expression? property9, System.Linq.Expressions.Expression? property10, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Linq.Expressions.Expression? property8, System.Linq.Expressions.Expression? property9, System.Linq.Expressions.Expression? property10, System.Linq.Expressions.Expression? property11, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Linq.Expressions.Expression? property8, System.Linq.Expressions.Expression? property9, System.Linq.Expressions.Expression? property10, System.Linq.Expressions.Expression? property11, System.Linq.Expressions.Expression? property12, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet?> selector) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, TRet?>> property1) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Func<T1?, TRet> selector) { }
-        public static System.IObservable<System.ValueTuple<T1?, T2?>> WhenAnyValue<TSender, T1, T2>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1, T2>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Func<T1?, T2?, TRet> selector) { }
-        public static System.IObservable<System.ValueTuple<T1?, T2?, T3?>> WhenAnyValue<TSender, T1, T2, T3>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1, T2, T3>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Func<T1?, T2?, T3?, TRet> selector) { }
-        public static System.IObservable<System.ValueTuple<T1?, T2?, T3?, T4?>> WhenAnyValue<TSender, T1, T2, T3, T4>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1, T2, T3, T4>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Func<T1?, T2?, T3?, T4?, TRet> selector) { }
-        public static System.IObservable<System.ValueTuple<T1?, T2?, T3?, T4?, T5?>> WhenAnyValue<TSender, T1, T2, T3, T4, T5>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Func<T1?, T2?, T3?, T4?, T5?, TRet> selector) { }
-        public static System.IObservable<System.ValueTuple<T1?, T2?, T3?, T4?, T5?, T6?>> WhenAnyValue<TSender, T1, T2, T3, T4, T5, T6>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, TRet> selector) { }
-        public static System.IObservable<System.ValueTuple<T1?, T2?, T3?, T4?, T5?, T6?, T7?>> WhenAnyValue<TSender, T1, T2, T3, T4, T5, T6, T7>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, TRet> selector) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, TRet> selector) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, TRet> selector) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, TRet> selector) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Linq.Expressions.Expression<System.Func<TSender, T11?>> property11, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, T11?, TRet> selector) { }
-        public static System.IObservable<TRet?> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Linq.Expressions.Expression<System.Func<TSender, T11?>> property11, System.Linq.Expressions.Expression<System.Func<TSender, T12?>> property12, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, T11?, T12?, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Func<ReactiveUI.IObservedChange<TSender, T1>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1, T2>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Func<ReactiveUI.IObservedChange<TSender, T1>, ReactiveUI.IObservedChange<TSender, T2>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1, T2, T3>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Func<ReactiveUI.IObservedChange<TSender, T1>, ReactiveUI.IObservedChange<TSender, T2>, ReactiveUI.IObservedChange<TSender, T3>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1, T2, T3, T4>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Func<ReactiveUI.IObservedChange<TSender, T1>, ReactiveUI.IObservedChange<TSender, T2>, ReactiveUI.IObservedChange<TSender, T3>, ReactiveUI.IObservedChange<TSender, T4>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1, T2, T3, T4, T5>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Func<ReactiveUI.IObservedChange<TSender, T1>, ReactiveUI.IObservedChange<TSender, T2>, ReactiveUI.IObservedChange<TSender, T3>, ReactiveUI.IObservedChange<TSender, T4>, ReactiveUI.IObservedChange<TSender, T5>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Func<ReactiveUI.IObservedChange<TSender, T1>, ReactiveUI.IObservedChange<TSender, T2>, ReactiveUI.IObservedChange<TSender, T3>, ReactiveUI.IObservedChange<TSender, T4>, ReactiveUI.IObservedChange<TSender, T5>, ReactiveUI.IObservedChange<TSender, T6>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Func<ReactiveUI.IObservedChange<TSender, T1>, ReactiveUI.IObservedChange<TSender, T2>, ReactiveUI.IObservedChange<TSender, T3>, ReactiveUI.IObservedChange<TSender, T4>, ReactiveUI.IObservedChange<TSender, T5>, ReactiveUI.IObservedChange<TSender, T6>, ReactiveUI.IObservedChange<TSender, T7>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Func<ReactiveUI.IObservedChange<TSender, T1>, ReactiveUI.IObservedChange<TSender, T2>, ReactiveUI.IObservedChange<TSender, T3>, ReactiveUI.IObservedChange<TSender, T4>, ReactiveUI.IObservedChange<TSender, T5>, ReactiveUI.IObservedChange<TSender, T6>, ReactiveUI.IObservedChange<TSender, T7>, ReactiveUI.IObservedChange<TSender, T8>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Func<ReactiveUI.IObservedChange<TSender, T1>, ReactiveUI.IObservedChange<TSender, T2>, ReactiveUI.IObservedChange<TSender, T3>, ReactiveUI.IObservedChange<TSender, T4>, ReactiveUI.IObservedChange<TSender, T5>, ReactiveUI.IObservedChange<TSender, T6>, ReactiveUI.IObservedChange<TSender, T7>, ReactiveUI.IObservedChange<TSender, T8>, ReactiveUI.IObservedChange<TSender, T9>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Func<ReactiveUI.IObservedChange<TSender, T1>, ReactiveUI.IObservedChange<TSender, T2>, ReactiveUI.IObservedChange<TSender, T3>, ReactiveUI.IObservedChange<TSender, T4>, ReactiveUI.IObservedChange<TSender, T5>, ReactiveUI.IObservedChange<TSender, T6>, ReactiveUI.IObservedChange<TSender, T7>, ReactiveUI.IObservedChange<TSender, T8>, ReactiveUI.IObservedChange<TSender, T9>, ReactiveUI.IObservedChange<TSender, T10>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Linq.Expressions.Expression<System.Func<TSender, T11?>> property11, System.Func<ReactiveUI.IObservedChange<TSender, T1>, ReactiveUI.IObservedChange<TSender, T2>, ReactiveUI.IObservedChange<TSender, T3>, ReactiveUI.IObservedChange<TSender, T4>, ReactiveUI.IObservedChange<TSender, T5>, ReactiveUI.IObservedChange<TSender, T6>, ReactiveUI.IObservedChange<TSender, T7>, ReactiveUI.IObservedChange<TSender, T8>, ReactiveUI.IObservedChange<TSender, T9>, ReactiveUI.IObservedChange<TSender, T10>, ReactiveUI.IObservedChange<TSender, T11>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Linq.Expressions.Expression<System.Func<TSender, T11?>> property11, System.Linq.Expressions.Expression<System.Func<TSender, T12?>> property12, System.Func<ReactiveUI.IObservedChange<TSender, T1>, ReactiveUI.IObservedChange<TSender, T2>, ReactiveUI.IObservedChange<TSender, T3>, ReactiveUI.IObservedChange<TSender, T4>, ReactiveUI.IObservedChange<TSender, T5>, ReactiveUI.IObservedChange<TSender, T6>, ReactiveUI.IObservedChange<TSender, T7>, ReactiveUI.IObservedChange<TSender, T8>, ReactiveUI.IObservedChange<TSender, T9>, ReactiveUI.IObservedChange<TSender, T10>, ReactiveUI.IObservedChange<TSender, T11>, ReactiveUI.IObservedChange<TSender, T12>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Linq.Expressions.Expression? property8, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Linq.Expressions.Expression? property8, System.Linq.Expressions.Expression? property9, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Linq.Expressions.Expression? property8, System.Linq.Expressions.Expression? property9, System.Linq.Expressions.Expression? property10, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Linq.Expressions.Expression? property8, System.Linq.Expressions.Expression? property9, System.Linq.Expressions.Expression? property10, System.Linq.Expressions.Expression? property11, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyDynamic<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression? property1, System.Linq.Expressions.Expression? property2, System.Linq.Expressions.Expression? property3, System.Linq.Expressions.Expression? property4, System.Linq.Expressions.Expression? property5, System.Linq.Expressions.Expression? property6, System.Linq.Expressions.Expression? property7, System.Linq.Expressions.Expression? property8, System.Linq.Expressions.Expression? property9, System.Linq.Expressions.Expression? property10, System.Linq.Expressions.Expression? property11, System.Linq.Expressions.Expression? property12, System.Func<ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, ReactiveUI.IObservedChange<TSender?, object?>, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, TRet?>> property1) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Func<T1, TRet> selector) { }
+        public static System.IObservable<System.ValueTuple<T1, T2>> WhenAnyValue<TSender, T1, T2>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1, T2>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Func<T1, T2, TRet> selector) { }
+        public static System.IObservable<System.ValueTuple<T1, T2, T3>> WhenAnyValue<TSender, T1, T2, T3>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1, T2, T3>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Func<T1, T2, T3, TRet> selector) { }
+        public static System.IObservable<System.ValueTuple<T1, T2, T3, T4>> WhenAnyValue<TSender, T1, T2, T3, T4>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1, T2, T3, T4>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Func<T1, T2, T3, T4, TRet> selector) { }
+        public static System.IObservable<System.ValueTuple<T1, T2, T3, T4, T5>> WhenAnyValue<TSender, T1, T2, T3, T4, T5>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Func<T1, T2, T3, T4, T5, TRet> selector) { }
+        public static System.IObservable<System.ValueTuple<T1, T2, T3, T4, T5, T6>> WhenAnyValue<TSender, T1, T2, T3, T4, T5, T6>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Func<T1, T2, T3, T4, T5, T6, TRet> selector) { }
+        public static System.IObservable<System.ValueTuple<T1, T2, T3, T4, T5, T6, T7>> WhenAnyValue<TSender, T1, T2, T3, T4, T5, T6, T7>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Func<T1, T2, T3, T4, T5, T6, T7, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Func<T1, T2, T3, T4, T5, T6, T7, T8, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Func<T1, T2, T3, T4, T5, T6, T7, T8, T9, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Func<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Linq.Expressions.Expression<System.Func<TSender, T11?>> property11, System.Func<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, TRet> selector) { }
+        public static System.IObservable<TRet> WhenAnyValue<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, T1?>> property1, System.Linq.Expressions.Expression<System.Func<TSender, T2?>> property2, System.Linq.Expressions.Expression<System.Func<TSender, T3?>> property3, System.Linq.Expressions.Expression<System.Func<TSender, T4?>> property4, System.Linq.Expressions.Expression<System.Func<TSender, T5?>> property5, System.Linq.Expressions.Expression<System.Func<TSender, T6?>> property6, System.Linq.Expressions.Expression<System.Func<TSender, T7?>> property7, System.Linq.Expressions.Expression<System.Func<TSender, T8?>> property8, System.Linq.Expressions.Expression<System.Func<TSender, T9?>> property9, System.Linq.Expressions.Expression<System.Func<TSender, T10?>> property10, System.Linq.Expressions.Expression<System.Func<TSender, T11?>> property11, System.Linq.Expressions.Expression<System.Func<TSender, T12?>> property12, System.Func<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, TRet> selector) { }
     }
     public static class WhenAnyObservableMixin
     {
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs8)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs8)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs9)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs9)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs10)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs10)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs10, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs11)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs10, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs11)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs10, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs11, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs12)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs10, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs11, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<TRet>?>> obs12)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1, T2>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Func<T1?, T2?, TRet?> selector)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet, T1, T2>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Func<T1?, T2?, TRet> selector)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1, T2, T3>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Func<T1?, T2?, T3?, TRet?> selector)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet, T1, T2, T3>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Func<T1?, T2?, T3?, TRet> selector)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Func<T1?, T2?, T3?, T4?, TRet?> selector)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Func<T1?, T2?, T3?, T4?, TRet> selector)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Func<T1?, T2?, T3?, T4?, T5?, TRet?> selector)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Func<T1?, T2?, T3?, T4?, T5?, TRet> selector)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, TRet?> selector)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, TRet> selector)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, TRet?> selector)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, TRet> selector)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T8>?>> obs8, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, TRet?> selector)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T8>?>> obs8, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, TRet> selector)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T8>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T9>?>> obs9, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, TRet?> selector)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T8>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T9>?>> obs9, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, TRet> selector)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T8>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T9>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T10>?>> obs10, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, TRet?> selector)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T8>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T9>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T10>?>> obs10, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, TRet> selector)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T8>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T9>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T10>?>> obs10, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T11>?>> obs11, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, T11?, TRet?> selector)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T8>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T9>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T10>?>> obs10, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T11>?>> obs11, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, T11?, TRet> selector)
             where TSender :  class { }
-        public static System.IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T8>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T9>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T10>?>> obs10, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T11>?>> obs11, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T12>?>> obs12, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, T11?, T12?, TRet?> selector)
+        public static System.IObservable<TRet> WhenAnyObservable<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>(this TSender? sender, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T1>?>> obs1, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T2>?>> obs2, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T3>?>> obs3, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T4>?>> obs4, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T5>?>> obs5, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T6>?>> obs6, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T7>?>> obs7, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T8>?>> obs8, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T9>?>> obs9, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T10>?>> obs10, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T11>?>> obs11, System.Linq.Expressions.Expression<System.Func<TSender, System.IObservable<T12>?>> obs12, System.Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, T11?, T12?, TRet> selector)
             where TSender :  class { }
     }
 }
diff --git a/src/ReactiveUI.Tests/Activation/ActivatingViewFetcher.cs b/src/ReactiveUI.Tests/Activation/ActivatingViewFetcher.cs
index eb8f77a1fd..468d644073 100644
--- a/src/ReactiveUI.Tests/Activation/ActivatingViewFetcher.cs
+++ b/src/ReactiveUI.Tests/Activation/ActivatingViewFetcher.cs
@@ -38,7 +38,7 @@ public class ActivatingViewFetcher : IActivationForViewFetcher
         /// <exception cref="ArgumentNullException">The view is null.</exception>
         public IObservable<bool> GetActivationForView(IActivatableView view)
         {
-            if (!(view is ActivatingView av))
+            if (view is not ActivatingView av)
             {
                 throw new ArgumentNullException(nameof(view));
             }
diff --git a/src/ReactiveUI.Tests/Activation/ActivatingViewTests.cs b/src/ReactiveUI.Tests/Activation/ActivatingViewTests.cs
index fbeef360d4..f14a24a0a5 100644
--- a/src/ReactiveUI.Tests/Activation/ActivatingViewTests.cs
+++ b/src/ReactiveUI.Tests/Activation/ActivatingViewTests.cs
@@ -87,9 +87,10 @@ public void SwitchingViewModelDeactivatesIt()
             using (locator.WithResolver())
             {
                 var vm = new ActivatingViewModel();
-                var fixture = new ActivatingView();
-
-                fixture.ViewModel = vm;
+                var fixture = new ActivatingView
+                {
+                    ViewModel = vm
+                };
                 Assert.Equal(0, vm.IsActiveCount);
                 Assert.Equal(0, fixture.IsActiveCount);
 
diff --git a/src/ReactiveUI.Tests/AutoPersist/AutoPersistHelperTest.cs b/src/ReactiveUI.Tests/AutoPersist/AutoPersistHelperTest.cs
index f8ae42f2db..515dec5761 100644
--- a/src/ReactiveUI.Tests/AutoPersist/AutoPersistHelperTest.cs
+++ b/src/ReactiveUI.Tests/AutoPersist/AutoPersistHelperTest.cs
@@ -7,7 +7,6 @@
 using System.Reactive;
 using System.Reactive.Linq;
 using System.Reactive.Subjects;
-using DynamicData.Binding;
 using Microsoft.Reactive.Testing;
 using ReactiveUI.Testing;
 using Xunit;
diff --git a/src/ReactiveUI.Tests/Commands/CreatesCommandBindingTests.cs b/src/ReactiveUI.Tests/Commands/CreatesCommandBindingTests.cs
index a5973646d2..4642a59b92 100644
--- a/src/ReactiveUI.Tests/Commands/CreatesCommandBindingTests.cs
+++ b/src/ReactiveUI.Tests/Commands/CreatesCommandBindingTests.cs
@@ -3,11 +3,8 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
-using System;
 using System.ComponentModel;
-using System.Reactive;
 using System.Reactive.Linq;
-using System.Reactive.Subjects;
 using Xunit;
 
 namespace ReactiveUI.Tests
diff --git a/src/ReactiveUI.Tests/Commands/ReactiveCommandTest.cs b/src/ReactiveUI.Tests/Commands/ReactiveCommandTest.cs
index 7149adeeb2..d0bf4d2e94 100644
--- a/src/ReactiveUI.Tests/Commands/ReactiveCommandTest.cs
+++ b/src/ReactiveUI.Tests/Commands/ReactiveCommandTest.cs
@@ -5,20 +5,15 @@
 
 using System;
 using System.Collections.Generic;
-using System.Collections.ObjectModel;
 using System.Reactive;
 using System.Reactive.Concurrency;
 using System.Reactive.Linq;
 using System.Reactive.Subjects;
 using System.Threading.Tasks;
 using System.Windows.Input;
-
 using DynamicData;
-
 using Microsoft.Reactive.Testing;
-
 using ReactiveUI.Testing;
-
 using Xunit;
 
 namespace ReactiveUI.Tests
diff --git a/src/ReactiveUI.Tests/Comparers/OrderedComparerTests.cs b/src/ReactiveUI.Tests/Comparers/OrderedComparerTests.cs
index 95b8f7a994..962c15887c 100644
--- a/src/ReactiveUI.Tests/Comparers/OrderedComparerTests.cs
+++ b/src/ReactiveUI.Tests/Comparers/OrderedComparerTests.cs
@@ -7,7 +7,6 @@
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
-using System.Text;
 using Xunit;
 
 namespace ReactiveUI.Tests
@@ -95,7 +94,7 @@ public void ChainOntoRegularIComparables()
         public void WorksWithAnonymousTypes()
         {
             var source = new List<string> { "abc", "bcd", "cde" };
-            var items = source.Select(x => new { FirstLetter = x[0], AllOfIt = x }).ToList();
+            var items = source.ConvertAll(x => new { FirstLetter = x[0], AllOfIt = x });
 
             items.Sort(OrderedComparer.For(items).OrderBy(x => x.FirstLetter));
             Assert.True(items.Select(x => x.FirstLetter).SequenceEqual("abc"));
diff --git a/src/ReactiveUI.Tests/InteractionBinding/InteractionBinderImplementationTests.cs b/src/ReactiveUI.Tests/InteractionBinding/InteractionBinderImplementationTests.cs
index 82c3f51d3e..dc8365cc60 100644
--- a/src/ReactiveUI.Tests/InteractionBinding/InteractionBinderImplementationTests.cs
+++ b/src/ReactiveUI.Tests/InteractionBinding/InteractionBinderImplementationTests.cs
@@ -8,9 +8,7 @@
 using System.Reactive.Linq;
 using System.Reactive.Threading.Tasks;
 using System.Threading.Tasks;
-
 using FluentAssertions;
-
 using Xunit;
 
 namespace ReactiveUI.Tests
diff --git a/src/ReactiveUI.Tests/Locator/DefaultViewLocatorTests.cs b/src/ReactiveUI.Tests/Locator/DefaultViewLocatorTests.cs
index 0427b4a639..2ff5ec26fc 100644
--- a/src/ReactiveUI.Tests/Locator/DefaultViewLocatorTests.cs
+++ b/src/ReactiveUI.Tests/Locator/DefaultViewLocatorTests.cs
@@ -4,10 +4,7 @@
 // See the LICENSE file in the project root for full license information.
 
 using System;
-using System.Diagnostics.CodeAnalysis;
-
 using Splat;
-
 using Xunit;
 
 namespace ReactiveUI.Tests
diff --git a/src/ReactiveUI.Tests/Mocks/CommandBindViewModel.cs b/src/ReactiveUI.Tests/Mocks/CommandBindViewModel.cs
index 30020f9db7..b133264830 100644
--- a/src/ReactiveUI.Tests/Mocks/CommandBindViewModel.cs
+++ b/src/ReactiveUI.Tests/Mocks/CommandBindViewModel.cs
@@ -3,12 +3,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Reactive;
-using System.Text;
-using System.Threading.Tasks;
 
 namespace ReactiveUI.Tests
 {
diff --git a/src/ReactiveUI.Tests/Mocks/FakeCollectionModel.cs b/src/ReactiveUI.Tests/Mocks/FakeCollectionModel.cs
index f8443c113d..d7ac866748 100644
--- a/src/ReactiveUI.Tests/Mocks/FakeCollectionModel.cs
+++ b/src/ReactiveUI.Tests/Mocks/FakeCollectionModel.cs
@@ -3,12 +3,6 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
 namespace ReactiveUI.Tests
 {
     /// <summary>
diff --git a/src/ReactiveUI.Tests/Mocks/FakeCollectionViewModel.cs b/src/ReactiveUI.Tests/Mocks/FakeCollectionViewModel.cs
index bfa52b81d6..8aa6c02eda 100644
--- a/src/ReactiveUI.Tests/Mocks/FakeCollectionViewModel.cs
+++ b/src/ReactiveUI.Tests/Mocks/FakeCollectionViewModel.cs
@@ -3,12 +3,6 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
 namespace ReactiveUI.Tests
 {
     /// <summary>
diff --git a/src/ReactiveUI.Tests/Mocks/FakeNestedViewModel.cs b/src/ReactiveUI.Tests/Mocks/FakeNestedViewModel.cs
index 0ca4b5d603..b8b97ab7e9 100644
--- a/src/ReactiveUI.Tests/Mocks/FakeNestedViewModel.cs
+++ b/src/ReactiveUI.Tests/Mocks/FakeNestedViewModel.cs
@@ -3,12 +3,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Reactive;
-using System.Text;
-using System.Threading.Tasks;
 
 namespace ReactiveUI.Tests
 {
diff --git a/src/ReactiveUI.Tests/Mocks/FakeViewModel.cs b/src/ReactiveUI.Tests/Mocks/FakeViewModel.cs
index 08709607e2..947191e2b5 100644
--- a/src/ReactiveUI.Tests/Mocks/FakeViewModel.cs
+++ b/src/ReactiveUI.Tests/Mocks/FakeViewModel.cs
@@ -3,12 +3,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Reactive;
-using System.Text;
-using System.Threading.Tasks;
 
 namespace ReactiveUI.Tests
 {
diff --git a/src/ReactiveUI.Tests/Mocks/PropertyBindModel.cs b/src/ReactiveUI.Tests/Mocks/PropertyBindModel.cs
index f37eded88f..e41f8fb2ef 100644
--- a/src/ReactiveUI.Tests/Mocks/PropertyBindModel.cs
+++ b/src/ReactiveUI.Tests/Mocks/PropertyBindModel.cs
@@ -3,12 +3,6 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
 namespace ReactiveUI.Tests
 {
     /// <summary>
diff --git a/src/ReactiveUI.Tests/Mocks/PropertyBindViewModel.cs b/src/ReactiveUI.Tests/Mocks/PropertyBindViewModel.cs
index 4e4bf42d4c..08432ae329 100644
--- a/src/ReactiveUI.Tests/Mocks/PropertyBindViewModel.cs
+++ b/src/ReactiveUI.Tests/Mocks/PropertyBindViewModel.cs
@@ -3,11 +3,6 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 using System.Windows;
 using DynamicData.Binding;
 
diff --git a/src/ReactiveUI.Tests/ObservableAsPropertyHelper/ObservableAsPropertyHelperTest.cs b/src/ReactiveUI.Tests/ObservableAsPropertyHelper/ObservableAsPropertyHelperTest.cs
index 784988f9bf..f6d11b472a 100644
--- a/src/ReactiveUI.Tests/ObservableAsPropertyHelper/ObservableAsPropertyHelperTest.cs
+++ b/src/ReactiveUI.Tests/ObservableAsPropertyHelper/ObservableAsPropertyHelperTest.cs
@@ -5,7 +5,6 @@
 
 using System;
 using System.Collections.Generic;
-using System.Diagnostics;
 using System.Linq;
 using System.Reactive.Concurrency;
 using System.Reactive.Disposables;
@@ -541,5 +540,26 @@ public void ToProperty_GivenIndexer_NotifiesOnExpectedPropertyName2() =>
                     var fixture = new OAPHIndexerTestFixture(2);
                 });
             });
+
+        /// <summary>
+        /// Nullables the types test shouldnt need decorators with toproperty.
+        /// </summary>
+        [Fact]
+        public void NullableTypesTestShouldntNeedDecorators2_ToProperty()
+        {
+            WhenAnyTestFixture? fixture = new();
+            fixture.WhenAnyValue(
+                x => x.ProjectService.ProjectsNullable,
+                x => x.AccountService.AccountUsersNullable)
+                   .Where(tuple => tuple.Item1.Any() && tuple.Item2.Any())
+                   .Select(tuple =>
+                   {
+                       var (projects, users) = tuple;
+                       return (int?)users.Values.Count(x => !string.IsNullOrWhiteSpace(x?.LastName));
+                   })
+                   .ToProperty(fixture, x => x.AccountsFound, out fixture._accountsFound);
+
+            Assert.Equal(fixture.AccountsFound, 3);
+        }
     }
 }
diff --git a/src/ReactiveUI.Tests/ObservedChanged/ObservedChangedMixinTest.cs b/src/ReactiveUI.Tests/ObservedChanged/ObservedChangedMixinTest.cs
index e8f6d1a995..5c52d20b9a 100644
--- a/src/ReactiveUI.Tests/ObservedChanged/ObservedChangedMixinTest.cs
+++ b/src/ReactiveUI.Tests/ObservedChanged/ObservedChangedMixinTest.cs
@@ -36,10 +36,7 @@ public void GetValueShouldActuallyReturnTheValue()
                 fixture.ObservableForProperty(x => x.IsOnlyOneWord)
                     .Select(x => x.GetValue())
                     .WhereNotNull()
-                    .Subscribe(x =>
-                    {
-                        output.Add(x);
-                    });
+                    .Subscribe(x => output.Add(x));
 
                 foreach (var v in input)
                 {
diff --git a/src/ReactiveUI.Tests/Platforms/windows-xaml/PropertyBindingTest.cs b/src/ReactiveUI.Tests/Platforms/windows-xaml/PropertyBindingTest.cs
index 33a6606cc3..1543d4a25b 100644
--- a/src/ReactiveUI.Tests/Platforms/windows-xaml/PropertyBindingTest.cs
+++ b/src/ReactiveUI.Tests/Platforms/windows-xaml/PropertyBindingTest.cs
@@ -16,7 +16,9 @@
 
 #if NETFX_CORE
 #else
+
 using FactAttribute = Xunit.WpfFactAttribute;
+
 #endif
 
 namespace ReactiveUI.Tests.Xaml
@@ -314,7 +316,7 @@ public void BindToNullShouldThrowHelpfulError()
             var view = new PropertyBindView { ViewModel = null };
 
             Assert.Throws<ArgumentNullException>(() =>
-                 view.WhenAnyValue(x => x.FakeControl!.NullHatingString!)
+                 view.WhenAnyValue(x => x.FakeControl.NullHatingString)
                      .BindTo(view.ViewModel, x => x.Property1));
         }
 
diff --git a/src/ReactiveUI.Tests/Platforms/windows-xaml/WhenAnyThroughDependencyObjectTests.cs b/src/ReactiveUI.Tests/Platforms/windows-xaml/WhenAnyThroughDependencyObjectTests.cs
index 39e05917bf..f13ff8ff33 100644
--- a/src/ReactiveUI.Tests/Platforms/windows-xaml/WhenAnyThroughDependencyObjectTests.cs
+++ b/src/ReactiveUI.Tests/Platforms/windows-xaml/WhenAnyThroughDependencyObjectTests.cs
@@ -9,7 +9,9 @@
 
 #if NETFX_CORE
 #else
+
 using FactAttribute = Xunit.WpfFactAttribute;
+
 #endif
 
 namespace ReactiveUI.Tests.Xaml
@@ -25,7 +27,7 @@ public class WhenAnyThroughDependencyObjectTests
         [Fact]
         public void WhenAnyThroughAViewShouldntGiveNullValues()
         {
-            var vm = new HostTestFixture
+            HostTestFixture? vm = new()
             {
                 Child = new TestFixture
                 {
@@ -42,7 +44,7 @@ public void WhenAnyThroughAViewShouldntGiveNullValues()
             Assert.Equal(0, output.Count);
             Assert.Null(fixture.ViewModel);
 
-            fixture.WhenAnyValue(x => x.ViewModel!.Child!.IsNotNullString!).Subscribe(output.Add);
+            fixture.WhenAnyValue(x => x.ViewModel!.Child!.IsNotNullString).Subscribe(output.Add);
 
             fixture.ViewModel = vm;
             Assert.Equal(1, output.Count);
diff --git a/src/ReactiveUI.Tests/Platforms/wpf/Mocks/CommandBindingView.cs b/src/ReactiveUI.Tests/Platforms/wpf/Mocks/CommandBindingView.cs
index 22232fc011..3c2a56587a 100644
--- a/src/ReactiveUI.Tests/Platforms/wpf/Mocks/CommandBindingView.cs
+++ b/src/ReactiveUI.Tests/Platforms/wpf/Mocks/CommandBindingView.cs
@@ -3,11 +3,6 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 using System.Windows.Controls;
 using ReactiveUI.Tests.Xaml;
 
diff --git a/src/ReactiveUI.Tests/Platforms/wpf/Mocks/CommandBindingViewModel.cs b/src/ReactiveUI.Tests/Platforms/wpf/Mocks/CommandBindingViewModel.cs
index f75f072db0..7de3e44125 100644
--- a/src/ReactiveUI.Tests/Platforms/wpf/Mocks/CommandBindingViewModel.cs
+++ b/src/ReactiveUI.Tests/Platforms/wpf/Mocks/CommandBindingViewModel.cs
@@ -3,13 +3,8 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using System.Reactive;
 using System.Reactive.Concurrency;
-using System.Text;
-using System.Threading.Tasks;
 
 namespace ReactiveUI.Tests.Wpf
 {
diff --git a/src/ReactiveUI.Tests/Platforms/wpf/Mocks/ExampleWindowView.cs b/src/ReactiveUI.Tests/Platforms/wpf/Mocks/ExampleWindowView.cs
index ae217c3de0..404e7304ec 100644
--- a/src/ReactiveUI.Tests/Platforms/wpf/Mocks/ExampleWindowView.cs
+++ b/src/ReactiveUI.Tests/Platforms/wpf/Mocks/ExampleWindowView.cs
@@ -3,12 +3,6 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
 namespace ReactiveUI.Tests.Wpf
 {
     public class ExampleWindowView : ReactiveWindow<ExampleWindowViewModel>
diff --git a/src/ReactiveUI.Tests/Platforms/wpf/Mocks/FakeXamlCommandBindingView.cs b/src/ReactiveUI.Tests/Platforms/wpf/Mocks/FakeXamlCommandBindingView.cs
index 234f988f0c..24d7dca131 100644
--- a/src/ReactiveUI.Tests/Platforms/wpf/Mocks/FakeXamlCommandBindingView.cs
+++ b/src/ReactiveUI.Tests/Platforms/wpf/Mocks/FakeXamlCommandBindingView.cs
@@ -3,9 +3,6 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
-using System;
-using System.Collections.Generic;
-using System.Text;
 using System.Windows.Controls;
 
 namespace ReactiveUI.Tests.Wpf
diff --git a/src/ReactiveUI.Tests/Platforms/wpf/Mocks/WpfTestUserControl.cs b/src/ReactiveUI.Tests/Platforms/wpf/Mocks/WpfTestUserControl.cs
index da98dc06a8..2a13dc563e 100644
--- a/src/ReactiveUI.Tests/Platforms/wpf/Mocks/WpfTestUserControl.cs
+++ b/src/ReactiveUI.Tests/Platforms/wpf/Mocks/WpfTestUserControl.cs
@@ -3,12 +3,6 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
 using System.Windows.Controls;
 
 namespace ReactiveUI.Tests.Wpf
diff --git a/src/ReactiveUI.Tests/Platforms/wpf/WpfCommandBindingImplementationTests.cs b/src/ReactiveUI.Tests/Platforms/wpf/WpfCommandBindingImplementationTests.cs
index a97c654730..5f309975b9 100644
--- a/src/ReactiveUI.Tests/Platforms/wpf/WpfCommandBindingImplementationTests.cs
+++ b/src/ReactiveUI.Tests/Platforms/wpf/WpfCommandBindingImplementationTests.cs
@@ -11,7 +11,6 @@
 using System.Windows.Controls;
 using System.Windows.Input;
 using FluentAssertions;
-using ReactiveUI;
 using Splat;
 using Xunit;
 using FactAttribute = Xunit.WpfFactAttribute;
diff --git a/src/ReactiveUI.Tests/Platforms/wpf/WpfViewDependencyResolverTests.cs b/src/ReactiveUI.Tests/Platforms/wpf/WpfViewDependencyResolverTests.cs
index b78fd92a81..c938b5cd4a 100644
--- a/src/ReactiveUI.Tests/Platforms/wpf/WpfViewDependencyResolverTests.cs
+++ b/src/ReactiveUI.Tests/Platforms/wpf/WpfViewDependencyResolverTests.cs
@@ -4,10 +4,6 @@
 // See the LICENSE file in the project root for full license information.
 
 using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 using Splat;
 using Xunit;
 
diff --git a/src/ReactiveUI.Tests/ReactiveObject/Mocks/AccountService.cs b/src/ReactiveUI.Tests/ReactiveObject/Mocks/AccountService.cs
new file mode 100644
index 0000000000..ae43590690
--- /dev/null
+++ b/src/ReactiveUI.Tests/ReactiveObject/Mocks/AccountService.cs
@@ -0,0 +1,48 @@
+// Copyright (c) 2021 .NET Foundation and Contributors. All rights reserved.
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for full license information.
+
+using System;
+using System.Collections.Generic;
+
+namespace ReactiveUI.Tests
+{
+    /// <summary>
+    /// Account Service.
+    /// </summary>
+    /// <seealso cref="ReactiveUI.ReactiveObject" />
+    public class AccountService : ReactiveObject
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="AccountService"/> class.
+        /// </summary>
+        public AccountService()
+        {
+            AccountUsers.Add(Guid.NewGuid(), new() { LastName = "Harris" });
+            AccountUsers.Add(Guid.NewGuid(), new() { LastName = "Jones" });
+            AccountUsers.Add(Guid.NewGuid(), new() { LastName = "Smith" });
+
+            AccountUsersNullable.Add(Guid.NewGuid(), new() { LastName = "Harris" });
+            AccountUsersNullable.Add(Guid.NewGuid(), new() { LastName = "Jones" });
+            AccountUsersNullable.Add(Guid.NewGuid(), new() { LastName = "Smith" });
+            AccountUsersNullable.Add(Guid.NewGuid(), null);
+        }
+
+        /// <summary>
+        /// Gets the account users.
+        /// </summary>
+        /// <value>
+        /// The account users.
+        /// </value>
+        public Dictionary<Guid, AccountUser> AccountUsers { get; } = new();
+
+        /// <summary>
+        /// Gets the account users nullable.
+        /// </summary>
+        /// <value>
+        /// The account users nullable.
+        /// </value>
+        public Dictionary<Guid, AccountUser?> AccountUsersNullable { get; } = new();
+    }
+}
diff --git a/src/ReactiveUI.Tests/ReactiveObject/Mocks/AccountUser.cs b/src/ReactiveUI.Tests/ReactiveObject/Mocks/AccountUser.cs
new file mode 100644
index 0000000000..cf74c549d4
--- /dev/null
+++ b/src/ReactiveUI.Tests/ReactiveObject/Mocks/AccountUser.cs
@@ -0,0 +1,32 @@
+// Copyright (c) 2021 .NET Foundation and Contributors. All rights reserved.
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for full license information.
+
+using System.Runtime.Serialization;
+
+namespace ReactiveUI.Tests
+{
+    /// <summary>
+    /// Account User.
+    /// </summary>
+    /// <seealso cref="ReactiveUI.ReactiveObject" />
+    [DataContract]
+    public class AccountUser : ReactiveObject
+    {
+        private string? _lastName;
+
+        /// <summary>
+        /// Gets or sets the last name.
+        /// </summary>
+        /// <value>
+        /// The last name.
+        /// </value>
+        [DataMember]
+        public string? LastName
+        {
+            get => _lastName;
+            set => this.RaiseAndSetIfChanged(ref _lastName, value);
+        }
+    }
+}
diff --git a/src/ReactiveUI.Tests/ReactiveObject/Mocks/OaphNameOfTestFixture.cs b/src/ReactiveUI.Tests/ReactiveObject/Mocks/OaphNameOfTestFixture.cs
index 479671cb24..700b4f0fb5 100644
--- a/src/ReactiveUI.Tests/ReactiveObject/Mocks/OaphNameOfTestFixture.cs
+++ b/src/ReactiveUI.Tests/ReactiveObject/Mocks/OaphNameOfTestFixture.cs
@@ -25,9 +25,7 @@ public class OaphNameOfTestFixture : TestFixture
         public OaphNameOfTestFixture()
         {
             this.WhenAnyValue(x => x.IsOnlyOneWord).Select(x => x ?? string.Empty).Select(x => x.Length >= 3 ? x.Substring(0, 3) : x).ToProperty(this, nameof(FirstThreeLettersOfOneWord), out _firstThreeLettersOfOneWord);
-#pragma warning disable CS8619 // Nullability of reference types in value doesn't match target type.
-            _lastThreeLettersOfOneWord = this.WhenAnyValue(x => x.IsOnlyOneWord).Select(x => x ?? string.Empty).Select(x => x.Length >= 3 ? x.Substring(x.Length - 3, 3) : x).ToProperty(this, nameof(LastThreeLettersOfOneWord));
-#pragma warning restore CS8619 // Nullability of reference types in value doesn't match target type.
+            _lastThreeLettersOfOneWord = this.WhenAnyValue(x => x.IsOnlyOneWord).Select(x => x ?? string.Empty).Select(x => x.Length >= 3 ? x.Substring(x.Length - 3, 3) : (string?)x).ToProperty(this, nameof(LastThreeLettersOfOneWord));
         }
 
         /// <summary>
diff --git a/src/ReactiveUI.Tests/ReactiveObject/Mocks/Project.cs b/src/ReactiveUI.Tests/ReactiveObject/Mocks/Project.cs
new file mode 100644
index 0000000000..ccb4872b95
--- /dev/null
+++ b/src/ReactiveUI.Tests/ReactiveObject/Mocks/Project.cs
@@ -0,0 +1,32 @@
+// Copyright (c) 2021 .NET Foundation and Contributors. All rights reserved.
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for full license information.
+
+using System.Runtime.Serialization;
+
+namespace ReactiveUI.Tests
+{
+    /// <summary>
+    /// Project.
+    /// </summary>
+    /// <seealso cref="ReactiveUI.ReactiveObject" />
+    [DataContract]
+    public class Project : ReactiveObject
+    {
+        private string? _name;
+
+        /// <summary>
+        /// Gets or sets the name.
+        /// </summary>
+        /// <value>
+        /// The name.
+        /// </value>
+        [DataMember]
+        public string? Name
+        {
+            get => _name;
+            set => this.RaiseAndSetIfChanged(ref _name, value);
+        }
+    }
+}
diff --git a/src/ReactiveUI.Tests/ReactiveObject/Mocks/ProjectService.cs b/src/ReactiveUI.Tests/ReactiveObject/Mocks/ProjectService.cs
new file mode 100644
index 0000000000..8efe690b63
--- /dev/null
+++ b/src/ReactiveUI.Tests/ReactiveObject/Mocks/ProjectService.cs
@@ -0,0 +1,51 @@
+// Copyright (c) 2021 .NET Foundation and Contributors. All rights reserved.
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for full license information.
+
+using System;
+using System.Collections.Generic;
+
+namespace ReactiveUI.Tests
+{
+    /// <summary>
+    /// Project Service.
+    /// </summary>
+    /// <seealso cref="ReactiveUI.ReactiveObject" />
+    public class ProjectService : ReactiveObject
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ProjectService"/> class.
+        /// </summary>
+        public ProjectService()
+        {
+            Projects.Add(Guid.NewGuid(), new() { Name = "Dummy1" });
+            Projects.Add(Guid.NewGuid(), new() { Name = "Dummy2" });
+            Projects.Add(Guid.NewGuid(), new() { Name = "Dummy3" });
+            Projects.Add(Guid.NewGuid(), new() { Name = "Dummy4" });
+            Projects.Add(Guid.NewGuid(), new() { Name = "Dummy5" });
+
+            ProjectsNullable.Add(Guid.NewGuid(), new() { Name = "Dummy1" });
+            ProjectsNullable.Add(Guid.NewGuid(), new() { Name = "Dummy2" });
+            ProjectsNullable.Add(Guid.NewGuid(), new() { Name = "Dummy3" });
+            ProjectsNullable.Add(Guid.NewGuid(), new() { Name = "Dummy4" });
+            ProjectsNullable.Add(Guid.NewGuid(), null);
+        }
+
+        /// <summary>
+        /// Gets the projects.
+        /// </summary>
+        /// <value>
+        /// The projects.
+        /// </value>
+        public Dictionary<Guid, Project> Projects { get; } = new();
+
+        /// <summary>
+        /// Gets the projects nullable.
+        /// </summary>
+        /// <value>
+        /// The projects nullable.
+        /// </value>
+        public Dictionary<Guid, Project?> ProjectsNullable { get; } = new();
+    }
+}
diff --git a/src/ReactiveUI.Tests/ReactiveObject/Mocks/WhenAnyTestFixture.cs b/src/ReactiveUI.Tests/ReactiveObject/Mocks/WhenAnyTestFixture.cs
new file mode 100644
index 0000000000..9a94a676e5
--- /dev/null
+++ b/src/ReactiveUI.Tests/ReactiveObject/Mocks/WhenAnyTestFixture.cs
@@ -0,0 +1,198 @@
+// Copyright (c) 2021 .NET Foundation and Contributors. All rights reserved.
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for full license information.
+
+using System.Runtime.Serialization;
+
+namespace ReactiveUI.Tests
+{
+    [DataContract]
+    public class WhenAnyTestFixture : ReactiveObject
+    {
+        [IgnoreDataMember]
+#pragma warning disable SA1401 // Fields should be private
+        internal ObservableAsPropertyHelper<int?>? _accountsFound;
+
+#pragma warning restore SA1401 // Fields should be private
+
+        [IgnoreDataMember]
+        private AccountService _accountService = new();
+
+        [IgnoreDataMember]
+        private ProjectService _projectService = new();
+
+        private string _value1 = "1";
+        private string? _value2;
+        private string _value3 = "3";
+        private string? _value4;
+        private string _value5 = "5";
+        private string? _value6;
+        private string _value7 = "7";
+        private string? _value8;
+        private string _value9 = "9";
+        private string? _value10;
+
+        /// <summary>
+        /// Gets or sets the account service.
+        /// </summary>
+        /// <value>
+        /// The account service.
+        /// </value>
+        [DataMember]
+        public AccountService AccountService
+        {
+            get => _accountService;
+            set => this.RaiseAndSetIfChanged(ref _accountService, value);
+        }
+
+        /// <summary>
+        /// Gets or sets the project service.
+        /// </summary>
+        /// <value>
+        /// The project service.
+        /// </value>
+        [DataMember]
+        public ProjectService ProjectService
+        {
+            get => _projectService;
+            set => this.RaiseAndSetIfChanged(ref _projectService, value);
+        }
+
+        /// <summary>
+        /// Gets the first three letters of one word.
+        /// </summary>
+        [IgnoreDataMember]
+        public int? AccountsFound => _accountsFound!.Value;
+
+        /// <summary>
+        /// Gets or sets the value1.
+        /// </summary>
+        /// <value>
+        /// The value1.
+        /// </value>
+        [DataMember]
+        public string Value1
+        {
+            get => _value1;
+            set => this.RaiseAndSetIfChanged(ref _value1, value);
+        }
+
+        /// <summary>
+        /// Gets or sets the value2.
+        /// </summary>
+        /// <value>
+        /// The value2.
+        /// </value>
+        [DataMember]
+        public string? Value2
+        {
+            get => _value2;
+            set => this.RaiseAndSetIfChanged(ref _value2, value);
+        }
+
+        /// <summary>
+        /// Gets or sets the value3.
+        /// </summary>
+        /// <value>
+        /// The value3.
+        /// </value>
+        [DataMember]
+        public string Value3
+        {
+            get => _value3;
+            set => this.RaiseAndSetIfChanged(ref _value3, value);
+        }
+
+        /// <summary>
+        /// Gets or sets the value4.
+        /// </summary>
+        /// <value>
+        /// The value4.
+        /// </value>
+        [DataMember]
+        public string? Value4
+        {
+            get => _value4;
+            set => this.RaiseAndSetIfChanged(ref _value4, value);
+        }
+
+        /// <summary>
+        /// Gets or sets the value5.
+        /// </summary>
+        /// <value>
+        /// The value5.
+        /// </value>
+        [DataMember]
+        public string Value5
+        {
+            get => _value5;
+            set => this.RaiseAndSetIfChanged(ref _value5, value);
+        }
+
+        /// <summary>
+        /// Gets or sets the value6.
+        /// </summary>
+        /// <value>
+        /// The value6.
+        /// </value>
+        [DataMember]
+        public string? Value6
+        {
+            get => _value6;
+            set => this.RaiseAndSetIfChanged(ref _value6, value);
+        }
+
+        /// <summary>
+        /// Gets or sets the value7.
+        /// </summary>
+        /// <value>
+        /// The value7.
+        /// </value>
+        [DataMember]
+        public string Value7
+        {
+            get => _value7;
+            set => this.RaiseAndSetIfChanged(ref _value7, value);
+        }
+
+        /// <summary>
+        /// Gets or sets the value8.
+        /// </summary>
+        /// <value>
+        /// The value8.
+        /// </value>
+        [DataMember]
+        public string? Value8
+        {
+            get => _value8;
+            set => this.RaiseAndSetIfChanged(ref _value8, value);
+        }
+
+        /// <summary>
+        /// Gets or sets the value9.
+        /// </summary>
+        /// <value>
+        /// The value9.
+        /// </value>
+        [DataMember]
+        public string Value9
+        {
+            get => _value9;
+            set => this.RaiseAndSetIfChanged(ref _value9, value);
+        }
+
+        /// <summary>
+        /// Gets or sets the value10.
+        /// </summary>
+        /// <value>
+        /// The value10.
+        /// </value>
+        [DataMember]
+        public string? Value10
+        {
+            get => _value10;
+            set => this.RaiseAndSetIfChanged(ref _value10, value);
+        }
+    }
+}
diff --git a/src/ReactiveUI.Tests/Resolvers/DependencyResolverTests.cs b/src/ReactiveUI.Tests/Resolvers/DependencyResolverTests.cs
index 3c5bae8953..107192077e 100644
--- a/src/ReactiveUI.Tests/Resolvers/DependencyResolverTests.cs
+++ b/src/ReactiveUI.Tests/Resolvers/DependencyResolverTests.cs
@@ -5,7 +5,6 @@
 
 using System;
 using System.Collections.Generic;
-using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 
 using FluentAssertions;
diff --git a/src/ReactiveUI.Tests/Resolvers/PocoObservableForPropertyTests.cs b/src/ReactiveUI.Tests/Resolvers/PocoObservableForPropertyTests.cs
index 50bde9adfb..44e0b2487e 100644
--- a/src/ReactiveUI.Tests/Resolvers/PocoObservableForPropertyTests.cs
+++ b/src/ReactiveUI.Tests/Resolvers/PocoObservableForPropertyTests.cs
@@ -6,14 +6,10 @@
 using System;
 using System.Collections.Generic;
 using System.ComponentModel;
-using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Linq.Expressions;
-
 using FluentAssertions;
-
 using Splat;
-
 using Xunit;
 
 namespace ReactiveUI.Tests
@@ -112,12 +108,14 @@ private class PocoType
         }
 
 #pragma warning disable CA1812 // Class is not instantiated
+
         private class INPCClass : INotifyPropertyChanged
         {
             public event PropertyChangedEventHandler? PropertyChanged;
 
             public void NotifyPropertyChanged() => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(string.Empty));
         }
+
 #pragma warning restore CA1812 // Class is not instantiated
 
         private class TestLogger : ILogger
diff --git a/src/ReactiveUI.Tests/Routing/Mocks/TestScreen.cs b/src/ReactiveUI.Tests/Routing/Mocks/TestScreen.cs
index 8038ab5cbb..96c4804fef 100644
--- a/src/ReactiveUI.Tests/Routing/Mocks/TestScreen.cs
+++ b/src/ReactiveUI.Tests/Routing/Mocks/TestScreen.cs
@@ -3,12 +3,6 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
 namespace ReactiveUI.Tests
 {
     public class TestScreen : ReactiveObject, IScreen
diff --git a/src/ReactiveUI.Tests/Routing/Mocks/TestViewModel.cs b/src/ReactiveUI.Tests/Routing/Mocks/TestViewModel.cs
index 5da595d12b..30be79dd1f 100644
--- a/src/ReactiveUI.Tests/Routing/Mocks/TestViewModel.cs
+++ b/src/ReactiveUI.Tests/Routing/Mocks/TestViewModel.cs
@@ -3,12 +3,6 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
 namespace ReactiveUI.Tests
 {
     public class TestViewModel : ReactiveObject, IRoutableViewModel
diff --git a/src/ReactiveUI.Tests/Routing/RoutableViewModelMixinTests.cs b/src/ReactiveUI.Tests/Routing/RoutableViewModelMixinTests.cs
index 6f6f873847..c258e462e5 100644
--- a/src/ReactiveUI.Tests/Routing/RoutableViewModelMixinTests.cs
+++ b/src/ReactiveUI.Tests/Routing/RoutableViewModelMixinTests.cs
@@ -9,8 +9,14 @@
 
 namespace ReactiveUI.Tests
 {
+    /// <summary>
+    /// Routable ViewModel MixinTests.
+    /// </summary>
     public class RoutableViewModelMixinTests
     {
+        /// <summary>
+        /// Whens the navigated to calls on navigated to when view model is first added.
+        /// </summary>
         [Fact]
         public void WhenNavigatedToCallsOnNavigatedToWhenViewModelIsFirstAdded()
         {
@@ -31,6 +37,9 @@ public void WhenNavigatedToCallsOnNavigatedToWhenViewModelIsFirstAdded()
             Assert.Equal(1, count);
         }
 
+        /// <summary>
+        /// Whens the navigated to calls on navigated to when view model returns to top of stack.
+        /// </summary>
         [Fact]
         public void WhenNavigatedToCallsOnNavigatedToWhenViewModelReturnsToTopOfStack()
         {
@@ -54,6 +63,9 @@ public void WhenNavigatedToCallsOnNavigatedToWhenViewModelReturnsToTopOfStack()
             Assert.Equal(2, count);
         }
 
+        /// <summary>
+        /// Whens the navigated to calls dispose when view model loses focus.
+        /// </summary>
         [Fact]
         public void WhenNavigatedToCallsDisposeWhenViewModelLosesFocus()
         {
@@ -77,6 +89,9 @@ public void WhenNavigatedToCallsDisposeWhenViewModelLosesFocus()
             Assert.Equal(1, count);
         }
 
+        /// <summary>
+        /// Whens the navigated to calls dispose when navigation stack is reset.
+        /// </summary>
         [Fact]
         public void WhenNavigatedToCallsDisposeWhenNavigationStackIsReset()
         {
@@ -100,6 +115,9 @@ public void WhenNavigatedToCallsDisposeWhenNavigationStackIsReset()
             Assert.Equal(1, count);
         }
 
+        /// <summary>
+        /// Whens the navigated to observable fires when view model added to navigation stack.
+        /// </summary>
         [Fact]
         public void WhenNavigatedToObservableFiresWhenViewModelAddedToNavigationStack()
         {
@@ -118,6 +136,9 @@ public void WhenNavigatedToObservableFiresWhenViewModelAddedToNavigationStack()
             Assert.Equal(1, count);
         }
 
+        /// <summary>
+        /// Whens the navigated to observable fires when view model returns to navigation stack.
+        /// </summary>
         [Fact]
         public void WhenNavigatedToObservableFiresWhenViewModelReturnsToNavigationStack()
         {
@@ -139,6 +160,9 @@ public void WhenNavigatedToObservableFiresWhenViewModelReturnsToNavigationStack(
             Assert.Equal(2, count);
         }
 
+        /// <summary>
+        /// Whens the navigated to observable completes when view model is removed from navigation stack.
+        /// </summary>
         [Fact]
         public void WhenNavigatedToObservableCompletesWhenViewModelIsRemovedFromNavigationStack()
         {
@@ -157,6 +181,9 @@ public void WhenNavigatedToObservableCompletesWhenViewModelIsRemovedFromNavigati
             Assert.Equal(1, count);
         }
 
+        /// <summary>
+        /// Whens the navigated to observable completes when navigation stack is reset.
+        /// </summary>
         [Fact]
         public void WhenNavigatedToObservableCompletesWhenNavigationStackIsReset()
         {
@@ -176,6 +203,9 @@ public void WhenNavigatedToObservableCompletesWhenNavigationStackIsReset()
             Assert.Equal(1, count);
         }
 
+        /// <summary>
+        /// Whens the navigating from observable fires when view model loses focus.
+        /// </summary>
         [Fact]
         public void WhenNavigatingFromObservableFiresWhenViewModelLosesFocus()
         {
@@ -195,6 +225,9 @@ public void WhenNavigatingFromObservableFiresWhenViewModelLosesFocus()
             Assert.Equal(1, count);
         }
 
+        /// <summary>
+        /// Whens the navigating from observable completes when view model is removed from navigation stack.
+        /// </summary>
         [Fact]
         public void WhenNavigatingFromObservableCompletesWhenViewModelIsRemovedFromNavigationStack()
         {
@@ -213,6 +246,9 @@ public void WhenNavigatingFromObservableCompletesWhenViewModelIsRemovedFromNavig
             Assert.Equal(1, count);
         }
 
+        /// <summary>
+        /// Whens the navigating from observable completes when navigation stack is reset.
+        /// </summary>
         [Fact]
         public void WhenNavigatingFromObservableCompletesWhenNavigationStackIsReset()
         {
diff --git a/src/ReactiveUI.Tests/Routing/RoutingStateTests.cs b/src/ReactiveUI.Tests/Routing/RoutingStateTests.cs
index 9fdabe3642..9e1464c618 100644
--- a/src/ReactiveUI.Tests/Routing/RoutingStateTests.cs
+++ b/src/ReactiveUI.Tests/Routing/RoutingStateTests.cs
@@ -4,7 +4,6 @@
 // See the LICENSE file in the project root for full license information.
 
 using System;
-using System.Collections.ObjectModel;
 using System.Linq;
 using System.Reactive.Concurrency;
 using System.Reactive.Linq;
@@ -17,6 +16,10 @@ namespace ReactiveUI.Tests
 {
     public class RoutingStateTests
     {
+        /// <summary>
+        /// Navigations the push pop test.
+        /// </summary>
+        /// <returns>A <see cref="Task"/> representing the asynchronous unit test.</returns>
         [Fact]
         public async Task NavigationPushPopTest()
         {
@@ -39,6 +42,10 @@ public async Task NavigationPushPopTest()
             Assert.Equal(1, fixture.NavigationStack.Count);
         }
 
+        /// <summary>
+        /// Currents the view model observable is accurate.
+        /// </summary>
+        /// <returns>A <see cref="Task"/> representing the asynchronous unit test.</returns>
         [Fact]
         public async Task CurrentViewModelObservableIsAccurate()
         {
@@ -87,6 +94,9 @@ public async Task CurrentViewModelObservableIsAccurate()
             Assert.Equal(null, (navigatedTo as TestViewModel)?.SomeProp);
         }
 
+        /// <summary>
+        /// Currents the view model observable is accurate via when any observable.
+        /// </summary>
         [Fact]
         public void CurrentViewModelObservableIsAccurateViaWhenAnyObservable()
         {
@@ -112,11 +122,16 @@ public void CurrentViewModelObservableIsAccurateViaWhenAnyObservable()
             Assert.Equal("A", (output.Last() as TestViewModel)?.SomeProp);
         }
 
+        /// <summary>
+        /// Navigates the and reset check navigation stack.
+        /// </summary>
         [Fact]
         public void NavigateAndResetCheckNavigationStack()
         {
-            var fixture = new TestScreen();
-            fixture.Router = new RoutingState();
+            var fixture = new TestScreen
+            {
+                Router = new RoutingState()
+            };
             var viewModel = new TestViewModel();
 
             Assert.False(fixture.Router.NavigationStack.Any());
@@ -127,6 +142,9 @@ public void NavigateAndResetCheckNavigationStack()
             Assert.True(ReferenceEquals(fixture.Router.NavigationStack.First(), viewModel));
         }
 
+        /// <summary>
+        /// Schedulers the is used for all commands.
+        /// </summary>
         [Fact]
         public void SchedulerIsUsedForAllCommands()
         {
diff --git a/src/ReactiveUI.Tests/RxAppTest.cs b/src/ReactiveUI.Tests/RxAppTest.cs
index e87448464d..939d877112 100644
--- a/src/ReactiveUI.Tests/RxAppTest.cs
+++ b/src/ReactiveUI.Tests/RxAppTest.cs
@@ -4,9 +4,7 @@
 // See the LICENSE file in the project root for full license information.
 
 using System.Diagnostics;
-using System.Linq;
 using System.Reactive.Concurrency;
-using Splat;
 using Xunit;
 
 namespace ReactiveUI.Tests
diff --git a/src/ReactiveUI.Tests/Suspension/SuspensionHostExtensionsTests.cs b/src/ReactiveUI.Tests/Suspension/SuspensionHostExtensionsTests.cs
index 6f938f9140..b244423d6c 100644
--- a/src/ReactiveUI.Tests/Suspension/SuspensionHostExtensionsTests.cs
+++ b/src/ReactiveUI.Tests/Suspension/SuspensionHostExtensionsTests.cs
@@ -16,8 +16,10 @@ public class SuspensionHostExtensionsTests
         [Fact]
         public void GetAppStateReturns()
         {
-            var fixture = new SuspensionHost();
-            fixture.AppState = new DummyAppState();
+            var fixture = new SuspensionHost
+            {
+                AppState = new DummyAppState()
+            };
 
             var result = fixture.GetAppState<DummyAppState>();
 
diff --git a/src/ReactiveUI.Tests/Utilities/CompatMixins.cs b/src/ReactiveUI.Tests/Utilities/CompatMixins.cs
index bbafc2491e..bd9915bd4d 100644
--- a/src/ReactiveUI.Tests/Utilities/CompatMixins.cs
+++ b/src/ReactiveUI.Tests/Utilities/CompatMixins.cs
@@ -6,8 +6,6 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 
 namespace ReactiveUI.Tests
 {
diff --git a/src/ReactiveUI.Tests/Utilities/CountingTestScheduler.cs b/src/ReactiveUI.Tests/Utilities/CountingTestScheduler.cs
index 83c09d9a52..fb2b6e109d 100644
--- a/src/ReactiveUI.Tests/Utilities/CountingTestScheduler.cs
+++ b/src/ReactiveUI.Tests/Utilities/CountingTestScheduler.cs
@@ -5,10 +5,7 @@
 
 using System;
 using System.Collections.Generic;
-using System.Linq;
 using System.Reactive.Concurrency;
-using System.Text;
-using System.Threading.Tasks;
 
 namespace ReactiveUI.Tests
 {
diff --git a/src/ReactiveUI.Tests/Utilities/EnumerableTestMixin.cs b/src/ReactiveUI.Tests/Utilities/EnumerableTestMixin.cs
index 7003e25884..b21f6a6592 100644
--- a/src/ReactiveUI.Tests/Utilities/EnumerableTestMixin.cs
+++ b/src/ReactiveUI.Tests/Utilities/EnumerableTestMixin.cs
@@ -7,8 +7,6 @@
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 using Xunit;
 
 namespace ReactiveUI.Tests
diff --git a/src/ReactiveUI.Tests/Utilities/JsonHelper.cs b/src/ReactiveUI.Tests/Utilities/JsonHelper.cs
index a2990317a9..ab778edd52 100644
--- a/src/ReactiveUI.Tests/Utilities/JsonHelper.cs
+++ b/src/ReactiveUI.Tests/Utilities/JsonHelper.cs
@@ -4,11 +4,8 @@
 // See the LICENSE file in the project root for full license information.
 
 using System;
-using System.Collections.Generic;
 using System.IO;
-using System.Linq;
 using System.Text;
-using System.Threading.Tasks;
 
 namespace ReactiveUI.Tests
 {
diff --git a/src/ReactiveUI.Tests/Utilities/TestLogger.cs b/src/ReactiveUI.Tests/Utilities/TestLogger.cs
index 6f83e5f5dd..8191a5eeb5 100644
--- a/src/ReactiveUI.Tests/Utilities/TestLogger.cs
+++ b/src/ReactiveUI.Tests/Utilities/TestLogger.cs
@@ -6,9 +6,6 @@
 using System;
 using System.Collections.Generic;
 using System.ComponentModel;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 using Splat;
 
 namespace ReactiveUI.Tests
diff --git a/src/ReactiveUI.Tests/Utilities/UseInvariantCulture.cs b/src/ReactiveUI.Tests/Utilities/UseInvariantCulture.cs
index fe6c8c612a..1c545a22e6 100644
--- a/src/ReactiveUI.Tests/Utilities/UseInvariantCulture.cs
+++ b/src/ReactiveUI.Tests/Utilities/UseInvariantCulture.cs
@@ -3,14 +3,9 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for full license information.
 
-using System;
-using System.Collections.Generic;
 using System.Globalization;
-using System.Linq;
 using System.Reflection;
-using System.Text;
 using System.Threading;
-using System.Threading.Tasks;
 
 using Xunit.Sdk;
 
diff --git a/src/ReactiveUI.Tests/WhenAny/ReactiveNotifyPropertyChangedMixinTest.cs b/src/ReactiveUI.Tests/WhenAny/ReactiveNotifyPropertyChangedMixinTest.cs
index bf412e1af5..848e6778ef 100644
--- a/src/ReactiveUI.Tests/WhenAny/ReactiveNotifyPropertyChangedMixinTest.cs
+++ b/src/ReactiveUI.Tests/WhenAny/ReactiveNotifyPropertyChangedMixinTest.cs
@@ -116,9 +116,9 @@ public void OFPChangingTheHostPropertyShouldFireAChildChangeNotificationOnlyIfTh
             new TestScheduler().With(scheduler =>
             {
                 HostTestFixture? fixture = new()
-                              {
-                                  Child = new TestFixture()
-                              };
+                {
+                    Child = new TestFixture()
+                };
                 fixture.ObservableForProperty(x => x.Child!.IsOnlyOneWord)
                        .ToObservableChangeSet(ImmediateScheduler.Instance)
                        .Bind(out var changes)
@@ -133,9 +133,9 @@ public void OFPChangingTheHostPropertyShouldFireAChildChangeNotificationOnlyIfTh
                 Assert.Equal(2, changes.Count);
 
                 fixture.Child = new TestFixture
-                                {
-                                    IsOnlyOneWord = "Bar"
-                                };
+                {
+                    IsOnlyOneWord = "Bar"
+                };
                 scheduler.Start();
                 Assert.Equal(2, changes.Count);
             });
@@ -176,9 +176,9 @@ public void OFPNamedPropertyTestBeforeChange() =>
             new TestScheduler().With(scheduler =>
             {
                 TestFixture? fixture = new()
-                              {
-                                  IsOnlyOneWord = "Pre"
-                              };
+                {
+                    IsOnlyOneWord = "Pre"
+                };
                 fixture.ObservableForProperty(x => x.IsOnlyOneWord, beforeChange: true)
                        .ToObservableChangeSet(ImmediateScheduler.Instance)
                        .Bind(out var changes)
@@ -205,9 +205,9 @@ public void OFPNamedPropertyTestNoSkipInitial() =>
             new TestScheduler().With(scheduler =>
             {
                 TestFixture? fixture = new()
-                              {
-                                  IsOnlyOneWord = "Pre"
-                              };
+                {
+                    IsOnlyOneWord = "Pre"
+                };
                 fixture.ObservableForProperty(x => x.IsOnlyOneWord, skipInitial: false)
                        .ToObservableChangeSet(ImmediateScheduler.Instance)
                        .Bind(out var changes)
@@ -261,9 +261,9 @@ public void OFPReplacingTheHostShouldResubscribeTheObservable() =>
             new TestScheduler().With(scheduler =>
             {
                 HostTestFixture? fixture = new()
-                              {
-                                  Child = new TestFixture()
-                              };
+                {
+                    Child = new TestFixture()
+                };
                 fixture.ObservableForProperty(x => x.Child!.IsOnlyOneWord)
                        .ToObservableChangeSet(ImmediateScheduler.Instance)
                        .Bind(out var changes)
@@ -306,9 +306,9 @@ public void OFPReplacingTheHostWithNullThenSettingItBackShouldResubscribeTheObse
             new TestScheduler().With(scheduler =>
             {
                 HostTestFixture? fixture = new()
-                              {
-                                  Child = new TestFixture()
-                              };
+                {
+                    Child = new TestFixture()
+                };
                 var fixtureProp = fixture.ObservableForProperty(x => x.Child!.IsOnlyOneWord);
                 fixtureProp
                        .ToObservableChangeSet(ImmediateScheduler.Instance)
@@ -346,9 +346,9 @@ public void OFPShouldWorkWithINPCObjectsToo() =>
             new TestScheduler().With(scheduler =>
             {
                 NonReactiveINPCObject? fixture = new()
-                              {
-                                  InpcProperty = null!
-                              };
+                {
+                    InpcProperty = null!
+                };
                 fixture.ObservableForProperty(x => x.InpcProperty.IsOnlyOneWord)
                        .ToObservableChangeSet(ImmediateScheduler.Instance)
                        .Bind(out var changes)
@@ -372,9 +372,9 @@ public void OFPSimpleChildPropertyTest() =>
             new TestScheduler().With(scheduler =>
             {
                 HostTestFixture? fixture = new()
-                              {
-                                  Child = new TestFixture()
-                              };
+                {
+                    Child = new TestFixture()
+                };
                 fixture.ObservableForProperty(x => x.Child!.IsOnlyOneWord)
                        .ToObservableChangeSet(ImmediateScheduler.Instance)
                        .Bind(out var changes)
@@ -580,9 +580,9 @@ public void WhenAnySmokeTest() =>
                 scheduler =>
                 {
                     HostTestFixture? fixture = new()
-                                  {
-                                      Child = new TestFixture()
-                                  };
+                    {
+                        Child = new TestFixture()
+                    };
                     fixture.SomeOtherParam = 5;
                     fixture.Child.IsNotNullString = "Foo";
 
@@ -592,10 +592,10 @@ public void WhenAnySmokeTest() =>
                         x => x.SomeOtherParam,
                         x => x.Child!.IsNotNullString,
                         (sop, nns) => new
-                                      {
-                                          sop,
-                                          nns
-                                      }).Subscribe(
+                        {
+                            sop,
+                            nns
+                        }).Subscribe(
                         x =>
                         {
                             output1.Add(x!.sop);
@@ -642,7 +642,7 @@ public void WhenAnyValueShouldWorkEvenWithNormalProperties()
             var output1 = new List<string?>();
             var output2 = new List<int>();
             fixture.WhenAnyValue(x => x.PocoProperty).Subscribe(output1.Add);
-            fixture.WhenAnyValue(x => x.IsOnlyOneWord, x => x!.Length).Subscribe(output2.Add);
+            fixture.WhenAnyValue(x => x.IsOnlyOneWord, x => x.Length).Subscribe(output2.Add);
 
             Assert.Equal(1, output1.Count);
             Assert.Equal("Bamf", output1[0]);
@@ -656,9 +656,9 @@ public void WhenAnyValueSmokeTest() =>
                 scheduler =>
                 {
                     HostTestFixture? fixture = new()
-                                  {
-                                      Child = new TestFixture()
-                                  };
+                    {
+                        Child = new TestFixture()
+                    };
                     fixture.SomeOtherParam = 5;
                     fixture.Child.IsNotNullString = "Foo";
 
@@ -668,10 +668,10 @@ public void WhenAnyValueSmokeTest() =>
                         x => x.SomeOtherParam,
                         x => x.Child!.IsNotNullString,
                         (sop, nns) => new
-                                      {
-                                          sop,
-                                          nns
-                                      }).Subscribe(
+                        {
+                            sop,
+                            nns
+                        }).Subscribe(
                         x =>
                         {
                             output1.Add(x!.sop);
@@ -763,5 +763,413 @@ public void WhenAnyValueUnsupportedExpressionType_Constant()
 
             Assert.Equal("Unsupported expression of type 'Constant'. Did you miss the member access prefix in the expression?", exception.Message);
         }
+
+        [Fact]
+        public void NullableTypesTestShouldntNeedDecorators()
+        {
+            WhenAnyTestFixture fixture = new();
+            IEnumerable<AccountUser?>? result = null;
+            fixture.WhenAnyValue(x => x.AccountService.AccountUsersNullable)
+                   .Where(users => users.Any())
+                   .Select(users => users.Values.Where(x => !string.IsNullOrWhiteSpace(x?.LastName)))
+                   .Subscribe(dict => result = dict);
+
+            Assert.Equal(result!.Count(), 3);
+        }
+
+        /// <summary>
+        /// Nullables the types test shouldnt need decorators2.
+        /// </summary>
+        [Fact]
+        public void NullableTypesTestShouldntNeedDecorators2()
+        {
+            WhenAnyTestFixture fixture = new();
+            IEnumerable<AccountUser?>? result = null;
+            fixture.WhenAnyValue(
+                x => x.ProjectService.ProjectsNullable,
+                x => x.AccountService.AccountUsersNullable)
+                   .Where(tuple => tuple.Item1.Any() && tuple.Item2.Any())
+                   .Select(tuple =>
+                   {
+                       var (projects, users) = tuple;
+                       return users.Values.Where(x => !string.IsNullOrWhiteSpace(x?.LastName));
+                   })
+                   .Subscribe(dict => result = dict);
+
+            Assert.Equal(result!.Count(), 3);
+        }
+
+        /// <summary>
+        /// Nons the nullable types test shouldnt need decorators.
+        /// </summary>
+        [Fact]
+        public void NonNullableTypesTestShouldntNeedDecorators()
+        {
+            WhenAnyTestFixture fixture = new();
+            IEnumerable<AccountUser>? result = null;
+            fixture.WhenAnyValue(x => x.AccountService.AccountUsers)
+                   .Where(users => users.Any())
+                   .Select(users => users.Values.Where(x => !string.IsNullOrWhiteSpace(x.LastName)))
+                   .Subscribe(dict => result = dict);
+
+            Assert.Equal(result!.Count(), 3);
+        }
+
+        /// <summary>
+        /// Nons the nullable types test shouldnt need decorators2.
+        /// </summary>
+        [Fact]
+        public void NonNullableTypesTestShouldntNeedDecorators2()
+        {
+            WhenAnyTestFixture fixture = new();
+            IEnumerable<AccountUser?>? result = null;
+            fixture.WhenAnyValue(
+                x => x.ProjectService.Projects,
+                x => x.AccountService.AccountUsers)
+                   .Where(tuple => tuple.Item1.Any() && tuple.Item2.Any())
+                   .Select(tuple =>
+                   {
+                       var (projects, users) = tuple;
+                       return users.Values.Where(x => !string.IsNullOrWhiteSpace(x?.LastName));
+                   })
+                   .Subscribe(dict => result = dict);
+
+            Assert.Equal(result!.Count(), 3);
+        }
+
+        /// <summary>
+        /// Whens any value with1 paramerters.
+        /// </summary>
+        [Fact]
+        public void WhenAnyValueWith1Paramerters()
+        {
+            WhenAnyTestFixture fixture = new();
+            string? result = null;
+            fixture.WhenAnyValue(
+                x => x.Value1)
+                   .Select(value =>
+                   {
+                       return value;
+                   })
+                   .Subscribe(value => result = value);
+
+            Assert.Equal(result, "1");
+        }
+
+        /// <summary>
+        /// Whens any value with2 paramerters returns tuple.
+        /// </summary>
+        [Fact]
+        public void WhenAnyValueWith2ParamertersReturnsTuple()
+        {
+            WhenAnyTestFixture fixture = new();
+            string? result = null;
+            fixture.WhenAnyValue(
+                x => x.Value1,
+                x => x.Value2)
+                   .Select(tuple =>
+                   {
+                       var (value1, value2) = tuple;
+                       return value1 + value2;
+                   })
+                   .Subscribe(value => result = value);
+
+            Assert.Equal(result, "1");
+        }
+
+        /// <summary>
+        /// Whens any value with2 paramerters returns values.
+        /// </summary>
+        [Fact]
+        public void WhenAnyValueWith2ParamertersReturnsValues()
+        {
+            WhenAnyTestFixture fixture = new();
+            string? result = null;
+            fixture.WhenAnyValue(
+                x => x.Value1,
+                x => x.Value2,
+                (v1, v2) => (v1, v2))
+                   .Select(tuple =>
+                   {
+                       var (value1, value2) = tuple;
+                       return value1 + value2;
+                   })
+                   .Subscribe(value => result = value);
+
+            Assert.Equal(result, "1");
+        }
+
+        /// <summary>
+        /// Whens any value with3 paramerters returns tuple.
+        /// </summary>
+        [Fact]
+        public void WhenAnyValueWith3ParamertersReturnsTuple()
+        {
+            WhenAnyTestFixture fixture = new();
+            string? result = null;
+            fixture.WhenAnyValue(
+                x => x.Value1,
+                x => x.Value2,
+                x => x.Value3)
+                   .Select(tuple =>
+                   {
+                       var (value1, value2, value3) = tuple;
+                       return value1 + value2 + value3;
+                   })
+                   .Subscribe(value => result = value);
+
+            Assert.Equal(result, "13");
+        }
+
+        /// <summary>
+        /// Whens any value with3 paramerters returns values.
+        /// </summary>
+        [Fact]
+        public void WhenAnyValueWith3ParamertersReturnsValues()
+        {
+            WhenAnyTestFixture fixture = new();
+            string? result = null;
+            fixture.WhenAnyValue(
+                x => x.Value1,
+                x => x.Value2,
+                x => x.Value3,
+                (v1, v2, v3) => (v1, v2, v3))
+                   .Select(tuple =>
+                   {
+                       var (value1, value2, value3) = tuple;
+                       return value1 + value2 + value3;
+                   })
+                   .Subscribe(value => result = value);
+
+            Assert.Equal(result, "13");
+        }
+
+        /// <summary>
+        /// Whens any value with4 paramerters returns tuple.
+        /// </summary>
+        [Fact]
+        public void WhenAnyValueWith4ParamertersReturnsTuple()
+        {
+            WhenAnyTestFixture fixture = new();
+            string? result = null;
+            fixture.WhenAnyValue(
+                x => x.Value1,
+                x => x.Value2,
+                x => x.Value3,
+                x => x.Value4)
+                   .Select(tuple =>
+                   {
+                       var (value1, value2, value3, value4) = tuple;
+                       return value1 + value2 + value3 + value4;
+                   })
+                   .Subscribe(value => result = value);
+
+            Assert.Equal(result, "13");
+        }
+
+        /// <summary>
+        /// Whens any value with4 paramerters returns values.
+        /// </summary>
+        [Fact]
+        public void WhenAnyValueWith4ParamertersReturnsValues()
+        {
+            WhenAnyTestFixture fixture = new();
+            string? result = null;
+            fixture.WhenAnyValue(
+                x => x.Value1,
+                x => x.Value2,
+                x => x.Value3,
+                x => x.Value4,
+                (v1, v2, v3, v4) => (v1, v2, v3, v4))
+                   .Select(tuple =>
+                   {
+                       var (value1, value2, value3, value4) = tuple;
+                       return value1 + value2 + value3 + value4;
+                   })
+                   .Subscribe(value => result = value);
+
+            Assert.Equal(result, "13");
+        }
+
+        /// <summary>
+        /// Whens any value with5 paramerters returns tuple.
+        /// </summary>
+        [Fact]
+        public void WhenAnyValueWith5ParamertersReturnsTuple()
+        {
+            WhenAnyTestFixture fixture = new();
+            string? result = null;
+            fixture.WhenAnyValue(
+                x => x.Value1,
+                x => x.Value2,
+                x => x.Value3,
+                x => x.Value4,
+                x => x.Value5)
+                   .Select(tuple =>
+                   {
+                       var (value1, value2, value3, value4, value5) = tuple;
+                       return value1 + value2 + value3 + value4 + value5;
+                   })
+                   .Subscribe(value => result = value);
+
+            Assert.Equal(result, "135");
+        }
+
+        /// <summary>
+        /// Whens any value with5 paramerters returns values.
+        /// </summary>
+        [Fact]
+        public void WhenAnyValueWith5ParamertersReturnsValues()
+        {
+            WhenAnyTestFixture fixture = new();
+            string? result = null;
+            fixture.WhenAnyValue(
+                x => x.Value1,
+                x => x.Value2,
+                x => x.Value3,
+                x => x.Value4,
+                x => x.Value5,
+                (v1, v2, v3, v4, v5) => (v1, v2, v3, v4, v5))
+                   .Select(tuple =>
+                   {
+                       var (value1, value2, value3, value4, value5) = tuple;
+                       return value1 + value2 + value3 + value4 + value5;
+                   })
+                   .Subscribe(value => result = value);
+
+            Assert.Equal(result, "135");
+        }
+
+        /// <summary>
+        /// Whens any value with6 paramerters returns tuple.
+        /// </summary>
+        [Fact]
+        public void WhenAnyValueWith6ParamertersReturnsTuple()
+        {
+            WhenAnyTestFixture fixture = new();
+            string? result = null;
+            fixture.WhenAnyValue(
+                x => x.Value1,
+                x => x.Value2,
+                x => x.Value3,
+                x => x.Value4,
+                x => x.Value5,
+                x => x.Value6)
+                   .Select(tuple =>
+                   {
+                       var (value1, value2, value3, value4, value5, value6) = tuple;
+                       return value1 + value2 + value3 + value4 + value5 + value6;
+                   })
+                   .Subscribe(value => result = value);
+
+            Assert.Equal(result, "135");
+        }
+
+        /// <summary>
+        /// Whens any value with6 paramerters returns values.
+        /// </summary>
+        [Fact]
+        public void WhenAnyValueWith6ParamertersReturnsValues()
+        {
+            WhenAnyTestFixture fixture = new();
+            string? result = null;
+            fixture.WhenAnyValue(
+                x => x.Value1,
+                x => x.Value2,
+                x => x.Value3,
+                x => x.Value4,
+                x => x.Value5,
+                x => x.Value6,
+                (v1, v2, v3, v4, v5, v6) => (v1, v2, v3, v4, v5, v6))
+                   .Select(tuple =>
+                   {
+                       var (value1, value2, value3, value4, value5, value6) = tuple;
+                       return value1 + value2 + value3 + value4 + value5 + value6;
+                   })
+                   .Subscribe(value => result = value);
+
+            Assert.Equal(result, "135");
+        }
+
+        /// <summary>
+        /// Whens any value with7 paramerters returns tuple.
+        /// </summary>
+        [Fact]
+        public void WhenAnyValueWith7ParamertersReturnsTuple()
+        {
+            WhenAnyTestFixture fixture = new();
+            string? result = null;
+            fixture.WhenAnyValue(
+                x => x.Value1,
+                x => x.Value2,
+                x => x.Value3,
+                x => x.Value4,
+                x => x.Value5,
+                x => x.Value6,
+                x => x.Value7)
+                   .Select(tuple =>
+                   {
+                       var (value1, value2, value3, value4, value5, value6, value7) = tuple;
+                       return value1 + value2 + value3 + value4 + value5 + value6 + value7;
+                   })
+                   .Subscribe(value => result = value);
+
+            Assert.Equal(result, "1357");
+        }
+
+        /// <summary>
+        /// Whens any value with7 paramerters returns values.
+        /// </summary>
+        [Fact]
+        public void WhenAnyValueWith7ParamertersReturnsValues()
+        {
+            WhenAnyTestFixture fixture = new();
+            string? result = null;
+            fixture.WhenAnyValue(
+                x => x.Value1,
+                x => x.Value2,
+                x => x.Value3,
+                x => x.Value4,
+                x => x.Value5,
+                x => x.Value6,
+                x => x.Value7,
+                (v1, v2, v3, v4, v5, v6, v7) => (v1, v2, v3, v4, v5, v6, v7))
+                   .Select(tuple =>
+                   {
+                       var (value1, value2, value3, value4, value5, value6, value7) = tuple;
+                       return value1 + value2 + value3 + value4 + value5 + value6 + value7;
+                   })
+                   .Subscribe(value => result = value);
+
+            Assert.Equal(result, "1357");
+        }
+
+        /// <summary>
+        /// Whens any value with8 paramerters returns values.
+        /// </summary>
+        [Fact]
+        public void WhenAnyValueWith8ParamertersReturnsValues()
+        {
+            WhenAnyTestFixture fixture = new();
+            string? result = null;
+            fixture.WhenAnyValue(
+                x => x.Value1,
+                x => x.Value2,
+                x => x.Value3,
+                x => x.Value4,
+                x => x.Value5,
+                x => x.Value6,
+                x => x.Value7,
+                x => x.Value8,
+                (v1, v2, v3, v4, v5, v6, v7, v8) => (v1, v2, v3, v4, v5, v6, v7, v8))
+                   .Select(tuple =>
+                   {
+                       var (value1, value2, value3, value4, value5, value6, value7, value8) = tuple;
+                       return value1 + value2 + value3 + value4 + value5 + value6 + value7 + value8;
+                   })
+                   .Subscribe(value => result = value);
+
+            Assert.Equal(result, "1357");
+        }
     }
 }
diff --git a/src/ReactiveUI/Mixins/ReactiveNotifyPropertyChangedMixin.cs b/src/ReactiveUI/Mixins/ReactiveNotifyPropertyChangedMixin.cs
index 5951831a38..f67a70a43d 100644
--- a/src/ReactiveUI/Mixins/ReactiveNotifyPropertyChangedMixin.cs
+++ b/src/ReactiveUI/Mixins/ReactiveNotifyPropertyChangedMixin.cs
@@ -47,7 +47,7 @@ public static class ReactiveNotifyPropertyChangedMixin
         /// with the initial value.</param>
         /// <returns>An Observable representing the property change
         /// notifications for the given property.</returns>
-        public static IObservable<IObservedChange<TSender, TValue?>> ObservableForProperty<TSender, TValue>(
+        public static IObservable<IObservedChange<TSender, TValue>> ObservableForProperty<TSender, TValue>(
                 this TSender? item,
                 Expression<Func<TSender, TValue?>> property,
                 bool beforeChange = false,
@@ -78,7 +78,7 @@ public static class ReactiveNotifyPropertyChangedMixin
              *  Resubscribe to new Baz, publish to Subject
              */
 
-            return SubscribeToExpressionChain<TSender, TValue?>(
+            return SubscribeToExpressionChain<TSender, TValue>(
                 item,
                 property.Body,
                 beforeChange,
diff --git a/src/ReactiveUI/VariadicTemplates.cs b/src/ReactiveUI/VariadicTemplates.cs
index c8f935b63d..907d1dc1a6 100644
--- a/src/ReactiveUI/VariadicTemplates.cs
+++ b/src/ReactiveUI/VariadicTemplates.cs
@@ -33,11 +33,11 @@ public static class WhenAnyMixin
         /// </summary>
         /// <param name="sender">The object where the property chain starts.</param>
         /// <param name="property1">The first property chain to reference. This will be a expression pointing to a end property or field.</param>
-        public static IObservable<TRet?> WhenAnyValue<TSender, TRet>(
+        public static IObservable<TRet> WhenAnyValue<TSender, TRet>(
             this TSender? sender,
             Expression<Func<TSender, TRet?>> property1)
         {
-            return sender.WhenAny(property1, (IObservedChange<TSender, TRet?> c1) => c1.Value);
+            return sender.WhenAny(property1, (IObservedChange<TSender, TRet> c1) => c1.Value);
         }
 
                                                                         
@@ -52,10 +52,10 @@ public static class WhenAnyMixin
         /// <param name="sender">The object where the property chain starts.</param>
         /// <param name="property1">The 1 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAnyValue<TSender, TRet, T1>(
+        public static IObservable<TRet> WhenAnyValue<TSender, TRet, T1>(
             this TSender? sender,
                         Expression<Func<TSender, T1?>> property1,
-                        Func<T1?, TRet> selector)
+                        Func<T1, TRet> selector)
         {
             return sender.WhenAny(property1,
                                 (c1) =>
@@ -72,10 +72,10 @@ public static class WhenAnyMixin
         /// <param name="sender">The object where the property chain starts.</param>
         /// <param name="property1">The 1 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAny<TSender, TRet, T1>(
+        public static IObservable<TRet> WhenAny<TSender, TRet, T1>(
                 this TSender? sender,
                             Expression<Func<TSender, T1?>> property1,
-                            Func<IObservedChange<TSender, T1?>, TRet?> selector)
+                            Func<IObservedChange<TSender, T1>, TRet> selector)
         {
                             return sender.ObservableForProperty(property1, false, false).Select(selector);
                     }
@@ -91,10 +91,10 @@ public static class WhenAnyMixin
         /// <param name="sender">The object where the property chain starts.</param>
         /// <param name="property1">The 1 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(
+        public static IObservable<TRet> WhenAnyDynamic<TSender, TRet>(
                 this TSender? sender,
                             Expression? property1,
-                            Func<IObservedChange<TSender?, object?>, TRet?> selector)
+                            Func<IObservedChange<TSender?, object?>, TRet> selector)
         {
                             return ReactiveNotifyPropertyChangedMixin
                     .SubscribeToExpressionChain<TSender,object?>(sender, property1, false, false).Select(selector);
@@ -110,7 +110,7 @@ public static class WhenAnyMixin
         /// <param name="sender">The object where the property chain starts.</param>
         /// <param name="property1">The 1 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property2">The 2 property chain to reference. This will be a expression pointing to a end property or field.</param>
-        public static IObservable<(T1?,T2?)> WhenAnyValue<TSender, T1,T2>(
+        public static IObservable<(T1,T2)> WhenAnyValue<TSender, T1,T2>(
             this TSender? sender,
                         Expression<Func<TSender, T1?>> property1,
                         Expression<Func<TSender, T2?>> property2
@@ -132,11 +132,11 @@ public static class WhenAnyMixin
         /// <param name="property1">The 1 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property2">The 2 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAnyValue<TSender, TRet, T1,T2>(
+        public static IObservable<TRet> WhenAnyValue<TSender, TRet, T1,T2>(
             this TSender? sender,
                         Expression<Func<TSender, T1?>> property1,
                         Expression<Func<TSender, T2?>> property2,
-                        Func<T1?,T2?, TRet> selector)
+                        Func<T1,T2, TRet> selector)
         {
             return sender.WhenAny(property1, property2,
                                 (c1, c2) =>
@@ -154,11 +154,11 @@ public static class WhenAnyMixin
         /// <param name="property1">The 1 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property2">The 2 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAny<TSender, TRet, T1,T2>(
+        public static IObservable<TRet> WhenAny<TSender, TRet, T1,T2>(
                 this TSender? sender,
                             Expression<Func<TSender, T1?>> property1,
                             Expression<Func<TSender, T2?>> property2,
-                            Func<IObservedChange<TSender, T1?>, IObservedChange<TSender, T2?>, TRet?> selector)
+                            Func<IObservedChange<TSender, T1>, IObservedChange<TSender, T2>, TRet> selector)
         {
                         return Observable.CombineLatest(
                                     sender.ObservableForProperty(property1, false, false),
@@ -179,11 +179,11 @@ public static class WhenAnyMixin
         /// <param name="property1">The 1 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property2">The 2 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(
+        public static IObservable<TRet> WhenAnyDynamic<TSender, TRet>(
                 this TSender? sender,
                             Expression? property1,
                             Expression? property2,
-                            Func<IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, TRet?> selector)
+                            Func<IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, TRet> selector)
         {
                         return Observable.CombineLatest(
                                     ReactiveNotifyPropertyChangedMixin
@@ -205,7 +205,7 @@ public static class WhenAnyMixin
         /// <param name="property1">The 1 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property2">The 2 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property3">The 3 property chain to reference. This will be a expression pointing to a end property or field.</param>
-        public static IObservable<(T1?,T2?,T3?)> WhenAnyValue<TSender, T1,T2,T3>(
+        public static IObservable<(T1,T2,T3)> WhenAnyValue<TSender, T1,T2,T3>(
             this TSender? sender,
                         Expression<Func<TSender, T1?>> property1,
                         Expression<Func<TSender, T2?>> property2,
@@ -229,12 +229,12 @@ public static class WhenAnyMixin
         /// <param name="property2">The 2 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property3">The 3 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAnyValue<TSender, TRet, T1,T2,T3>(
+        public static IObservable<TRet> WhenAnyValue<TSender, TRet, T1,T2,T3>(
             this TSender? sender,
                         Expression<Func<TSender, T1?>> property1,
                         Expression<Func<TSender, T2?>> property2,
                         Expression<Func<TSender, T3?>> property3,
-                        Func<T1?,T2?,T3?, TRet> selector)
+                        Func<T1,T2,T3, TRet> selector)
         {
             return sender.WhenAny(property1, property2, property3,
                                 (c1, c2, c3) =>
@@ -253,12 +253,12 @@ public static class WhenAnyMixin
         /// <param name="property2">The 2 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property3">The 3 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAny<TSender, TRet, T1,T2,T3>(
+        public static IObservable<TRet> WhenAny<TSender, TRet, T1,T2,T3>(
                 this TSender? sender,
                             Expression<Func<TSender, T1?>> property1,
                             Expression<Func<TSender, T2?>> property2,
                             Expression<Func<TSender, T3?>> property3,
-                            Func<IObservedChange<TSender, T1?>, IObservedChange<TSender, T2?>, IObservedChange<TSender, T3?>, TRet?> selector)
+                            Func<IObservedChange<TSender, T1>, IObservedChange<TSender, T2>, IObservedChange<TSender, T3>, TRet> selector)
         {
                         return Observable.CombineLatest(
                                     sender.ObservableForProperty(property1, false, false),
@@ -281,12 +281,12 @@ public static class WhenAnyMixin
         /// <param name="property2">The 2 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property3">The 3 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(
+        public static IObservable<TRet> WhenAnyDynamic<TSender, TRet>(
                 this TSender? sender,
                             Expression? property1,
                             Expression? property2,
                             Expression? property3,
-                            Func<IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, TRet?> selector)
+                            Func<IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, TRet> selector)
         {
                         return Observable.CombineLatest(
                                     ReactiveNotifyPropertyChangedMixin
@@ -311,7 +311,7 @@ public static class WhenAnyMixin
         /// <param name="property2">The 2 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property3">The 3 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property4">The 4 property chain to reference. This will be a expression pointing to a end property or field.</param>
-        public static IObservable<(T1?,T2?,T3?,T4?)> WhenAnyValue<TSender, T1,T2,T3,T4>(
+        public static IObservable<(T1,T2,T3,T4)> WhenAnyValue<TSender, T1,T2,T3,T4>(
             this TSender? sender,
                         Expression<Func<TSender, T1?>> property1,
                         Expression<Func<TSender, T2?>> property2,
@@ -337,13 +337,13 @@ public static class WhenAnyMixin
         /// <param name="property3">The 3 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property4">The 4 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAnyValue<TSender, TRet, T1,T2,T3,T4>(
+        public static IObservable<TRet> WhenAnyValue<TSender, TRet, T1,T2,T3,T4>(
             this TSender? sender,
                         Expression<Func<TSender, T1?>> property1,
                         Expression<Func<TSender, T2?>> property2,
                         Expression<Func<TSender, T3?>> property3,
                         Expression<Func<TSender, T4?>> property4,
-                        Func<T1?,T2?,T3?,T4?, TRet> selector)
+                        Func<T1,T2,T3,T4, TRet> selector)
         {
             return sender.WhenAny(property1, property2, property3, property4,
                                 (c1, c2, c3, c4) =>
@@ -363,13 +363,13 @@ public static class WhenAnyMixin
         /// <param name="property3">The 3 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property4">The 4 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAny<TSender, TRet, T1,T2,T3,T4>(
+        public static IObservable<TRet> WhenAny<TSender, TRet, T1,T2,T3,T4>(
                 this TSender? sender,
                             Expression<Func<TSender, T1?>> property1,
                             Expression<Func<TSender, T2?>> property2,
                             Expression<Func<TSender, T3?>> property3,
                             Expression<Func<TSender, T4?>> property4,
-                            Func<IObservedChange<TSender, T1?>, IObservedChange<TSender, T2?>, IObservedChange<TSender, T3?>, IObservedChange<TSender, T4?>, TRet?> selector)
+                            Func<IObservedChange<TSender, T1>, IObservedChange<TSender, T2>, IObservedChange<TSender, T3>, IObservedChange<TSender, T4>, TRet> selector)
         {
                         return Observable.CombineLatest(
                                     sender.ObservableForProperty(property1, false, false),
@@ -394,13 +394,13 @@ public static class WhenAnyMixin
         /// <param name="property3">The 3 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property4">The 4 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(
+        public static IObservable<TRet> WhenAnyDynamic<TSender, TRet>(
                 this TSender? sender,
                             Expression? property1,
                             Expression? property2,
                             Expression? property3,
                             Expression? property4,
-                            Func<IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, TRet?> selector)
+                            Func<IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, TRet> selector)
         {
                         return Observable.CombineLatest(
                                     ReactiveNotifyPropertyChangedMixin
@@ -428,7 +428,7 @@ public static class WhenAnyMixin
         /// <param name="property3">The 3 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property4">The 4 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property5">The 5 property chain to reference. This will be a expression pointing to a end property or field.</param>
-        public static IObservable<(T1?,T2?,T3?,T4?,T5?)> WhenAnyValue<TSender, T1,T2,T3,T4,T5>(
+        public static IObservable<(T1,T2,T3,T4,T5)> WhenAnyValue<TSender, T1,T2,T3,T4,T5>(
             this TSender? sender,
                         Expression<Func<TSender, T1?>> property1,
                         Expression<Func<TSender, T2?>> property2,
@@ -456,14 +456,14 @@ public static class WhenAnyMixin
         /// <param name="property4">The 4 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property5">The 5 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAnyValue<TSender, TRet, T1,T2,T3,T4,T5>(
+        public static IObservable<TRet> WhenAnyValue<TSender, TRet, T1,T2,T3,T4,T5>(
             this TSender? sender,
                         Expression<Func<TSender, T1?>> property1,
                         Expression<Func<TSender, T2?>> property2,
                         Expression<Func<TSender, T3?>> property3,
                         Expression<Func<TSender, T4?>> property4,
                         Expression<Func<TSender, T5?>> property5,
-                        Func<T1?,T2?,T3?,T4?,T5?, TRet> selector)
+                        Func<T1,T2,T3,T4,T5, TRet> selector)
         {
             return sender.WhenAny(property1, property2, property3, property4, property5,
                                 (c1, c2, c3, c4, c5) =>
@@ -484,14 +484,14 @@ public static class WhenAnyMixin
         /// <param name="property4">The 4 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property5">The 5 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAny<TSender, TRet, T1,T2,T3,T4,T5>(
+        public static IObservable<TRet> WhenAny<TSender, TRet, T1,T2,T3,T4,T5>(
                 this TSender? sender,
                             Expression<Func<TSender, T1?>> property1,
                             Expression<Func<TSender, T2?>> property2,
                             Expression<Func<TSender, T3?>> property3,
                             Expression<Func<TSender, T4?>> property4,
                             Expression<Func<TSender, T5?>> property5,
-                            Func<IObservedChange<TSender, T1?>, IObservedChange<TSender, T2?>, IObservedChange<TSender, T3?>, IObservedChange<TSender, T4?>, IObservedChange<TSender, T5?>, TRet?> selector)
+                            Func<IObservedChange<TSender, T1>, IObservedChange<TSender, T2>, IObservedChange<TSender, T3>, IObservedChange<TSender, T4>, IObservedChange<TSender, T5>, TRet> selector)
         {
                         return Observable.CombineLatest(
                                     sender.ObservableForProperty(property1, false, false),
@@ -518,14 +518,14 @@ public static class WhenAnyMixin
         /// <param name="property4">The 4 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property5">The 5 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(
+        public static IObservable<TRet> WhenAnyDynamic<TSender, TRet>(
                 this TSender? sender,
                             Expression? property1,
                             Expression? property2,
                             Expression? property3,
                             Expression? property4,
                             Expression? property5,
-                            Func<IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, TRet?> selector)
+                            Func<IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, TRet> selector)
         {
                         return Observable.CombineLatest(
                                     ReactiveNotifyPropertyChangedMixin
@@ -556,7 +556,7 @@ public static class WhenAnyMixin
         /// <param name="property4">The 4 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property5">The 5 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property6">The 6 property chain to reference. This will be a expression pointing to a end property or field.</param>
-        public static IObservable<(T1?,T2?,T3?,T4?,T5?,T6?)> WhenAnyValue<TSender, T1,T2,T3,T4,T5,T6>(
+        public static IObservable<(T1,T2,T3,T4,T5,T6)> WhenAnyValue<TSender, T1,T2,T3,T4,T5,T6>(
             this TSender? sender,
                         Expression<Func<TSender, T1?>> property1,
                         Expression<Func<TSender, T2?>> property2,
@@ -586,7 +586,7 @@ public static class WhenAnyMixin
         /// <param name="property5">The 5 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property6">The 6 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAnyValue<TSender, TRet, T1,T2,T3,T4,T5,T6>(
+        public static IObservable<TRet> WhenAnyValue<TSender, TRet, T1,T2,T3,T4,T5,T6>(
             this TSender? sender,
                         Expression<Func<TSender, T1?>> property1,
                         Expression<Func<TSender, T2?>> property2,
@@ -594,7 +594,7 @@ public static class WhenAnyMixin
                         Expression<Func<TSender, T4?>> property4,
                         Expression<Func<TSender, T5?>> property5,
                         Expression<Func<TSender, T6?>> property6,
-                        Func<T1?,T2?,T3?,T4?,T5?,T6?, TRet> selector)
+                        Func<T1,T2,T3,T4,T5,T6, TRet> selector)
         {
             return sender.WhenAny(property1, property2, property3, property4, property5, property6,
                                 (c1, c2, c3, c4, c5, c6) =>
@@ -616,7 +616,7 @@ public static class WhenAnyMixin
         /// <param name="property5">The 5 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property6">The 6 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAny<TSender, TRet, T1,T2,T3,T4,T5,T6>(
+        public static IObservable<TRet> WhenAny<TSender, TRet, T1,T2,T3,T4,T5,T6>(
                 this TSender? sender,
                             Expression<Func<TSender, T1?>> property1,
                             Expression<Func<TSender, T2?>> property2,
@@ -624,7 +624,7 @@ public static class WhenAnyMixin
                             Expression<Func<TSender, T4?>> property4,
                             Expression<Func<TSender, T5?>> property5,
                             Expression<Func<TSender, T6?>> property6,
-                            Func<IObservedChange<TSender, T1?>, IObservedChange<TSender, T2?>, IObservedChange<TSender, T3?>, IObservedChange<TSender, T4?>, IObservedChange<TSender, T5?>, IObservedChange<TSender, T6?>, TRet?> selector)
+                            Func<IObservedChange<TSender, T1>, IObservedChange<TSender, T2>, IObservedChange<TSender, T3>, IObservedChange<TSender, T4>, IObservedChange<TSender, T5>, IObservedChange<TSender, T6>, TRet> selector)
         {
                         return Observable.CombineLatest(
                                     sender.ObservableForProperty(property1, false, false),
@@ -653,7 +653,7 @@ public static class WhenAnyMixin
         /// <param name="property5">The 5 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property6">The 6 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(
+        public static IObservable<TRet> WhenAnyDynamic<TSender, TRet>(
                 this TSender? sender,
                             Expression? property1,
                             Expression? property2,
@@ -661,7 +661,7 @@ public static class WhenAnyMixin
                             Expression? property4,
                             Expression? property5,
                             Expression? property6,
-                            Func<IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, TRet?> selector)
+                            Func<IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, TRet> selector)
         {
                         return Observable.CombineLatest(
                                     ReactiveNotifyPropertyChangedMixin
@@ -695,7 +695,7 @@ public static class WhenAnyMixin
         /// <param name="property5">The 5 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property6">The 6 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property7">The 7 property chain to reference. This will be a expression pointing to a end property or field.</param>
-        public static IObservable<(T1?,T2?,T3?,T4?,T5?,T6?,T7?)> WhenAnyValue<TSender, T1,T2,T3,T4,T5,T6,T7>(
+        public static IObservable<(T1,T2,T3,T4,T5,T6,T7)> WhenAnyValue<TSender, T1,T2,T3,T4,T5,T6,T7>(
             this TSender? sender,
                         Expression<Func<TSender, T1?>> property1,
                         Expression<Func<TSender, T2?>> property2,
@@ -727,7 +727,7 @@ public static class WhenAnyMixin
         /// <param name="property6">The 6 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property7">The 7 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAnyValue<TSender, TRet, T1,T2,T3,T4,T5,T6,T7>(
+        public static IObservable<TRet> WhenAnyValue<TSender, TRet, T1,T2,T3,T4,T5,T6,T7>(
             this TSender? sender,
                         Expression<Func<TSender, T1?>> property1,
                         Expression<Func<TSender, T2?>> property2,
@@ -736,7 +736,7 @@ public static class WhenAnyMixin
                         Expression<Func<TSender, T5?>> property5,
                         Expression<Func<TSender, T6?>> property6,
                         Expression<Func<TSender, T7?>> property7,
-                        Func<T1?,T2?,T3?,T4?,T5?,T6?,T7?, TRet> selector)
+                        Func<T1,T2,T3,T4,T5,T6,T7, TRet> selector)
         {
             return sender.WhenAny(property1, property2, property3, property4, property5, property6, property7,
                                 (c1, c2, c3, c4, c5, c6, c7) =>
@@ -759,7 +759,7 @@ public static class WhenAnyMixin
         /// <param name="property6">The 6 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property7">The 7 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAny<TSender, TRet, T1,T2,T3,T4,T5,T6,T7>(
+        public static IObservable<TRet> WhenAny<TSender, TRet, T1,T2,T3,T4,T5,T6,T7>(
                 this TSender? sender,
                             Expression<Func<TSender, T1?>> property1,
                             Expression<Func<TSender, T2?>> property2,
@@ -768,7 +768,7 @@ public static class WhenAnyMixin
                             Expression<Func<TSender, T5?>> property5,
                             Expression<Func<TSender, T6?>> property6,
                             Expression<Func<TSender, T7?>> property7,
-                            Func<IObservedChange<TSender, T1?>, IObservedChange<TSender, T2?>, IObservedChange<TSender, T3?>, IObservedChange<TSender, T4?>, IObservedChange<TSender, T5?>, IObservedChange<TSender, T6?>, IObservedChange<TSender, T7?>, TRet?> selector)
+                            Func<IObservedChange<TSender, T1>, IObservedChange<TSender, T2>, IObservedChange<TSender, T3>, IObservedChange<TSender, T4>, IObservedChange<TSender, T5>, IObservedChange<TSender, T6>, IObservedChange<TSender, T7>, TRet> selector)
         {
                         return Observable.CombineLatest(
                                     sender.ObservableForProperty(property1, false, false),
@@ -799,7 +799,7 @@ public static class WhenAnyMixin
         /// <param name="property6">The 6 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property7">The 7 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(
+        public static IObservable<TRet> WhenAnyDynamic<TSender, TRet>(
                 this TSender? sender,
                             Expression? property1,
                             Expression? property2,
@@ -808,7 +808,7 @@ public static class WhenAnyMixin
                             Expression? property5,
                             Expression? property6,
                             Expression? property7,
-                            Func<IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, TRet?> selector)
+                            Func<IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, TRet> selector)
         {
                         return Observable.CombineLatest(
                                     ReactiveNotifyPropertyChangedMixin
@@ -847,7 +847,7 @@ public static class WhenAnyMixin
         /// <param name="property7">The 7 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property8">The 8 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAnyValue<TSender, TRet, T1,T2,T3,T4,T5,T6,T7,T8>(
+        public static IObservable<TRet> WhenAnyValue<TSender, TRet, T1,T2,T3,T4,T5,T6,T7,T8>(
             this TSender? sender,
                         Expression<Func<TSender, T1?>> property1,
                         Expression<Func<TSender, T2?>> property2,
@@ -857,7 +857,7 @@ public static class WhenAnyMixin
                         Expression<Func<TSender, T6?>> property6,
                         Expression<Func<TSender, T7?>> property7,
                         Expression<Func<TSender, T8?>> property8,
-                        Func<T1?,T2?,T3?,T4?,T5?,T6?,T7?,T8?, TRet> selector)
+                        Func<T1,T2,T3,T4,T5,T6,T7,T8, TRet> selector)
         {
             return sender.WhenAny(property1, property2, property3, property4, property5, property6, property7, property8,
                                 (c1, c2, c3, c4, c5, c6, c7, c8) =>
@@ -881,7 +881,7 @@ public static class WhenAnyMixin
         /// <param name="property7">The 7 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property8">The 8 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAny<TSender, TRet, T1,T2,T3,T4,T5,T6,T7,T8>(
+        public static IObservable<TRet> WhenAny<TSender, TRet, T1,T2,T3,T4,T5,T6,T7,T8>(
                 this TSender? sender,
                             Expression<Func<TSender, T1?>> property1,
                             Expression<Func<TSender, T2?>> property2,
@@ -891,7 +891,7 @@ public static class WhenAnyMixin
                             Expression<Func<TSender, T6?>> property6,
                             Expression<Func<TSender, T7?>> property7,
                             Expression<Func<TSender, T8?>> property8,
-                            Func<IObservedChange<TSender, T1?>, IObservedChange<TSender, T2?>, IObservedChange<TSender, T3?>, IObservedChange<TSender, T4?>, IObservedChange<TSender, T5?>, IObservedChange<TSender, T6?>, IObservedChange<TSender, T7?>, IObservedChange<TSender, T8?>, TRet?> selector)
+                            Func<IObservedChange<TSender, T1>, IObservedChange<TSender, T2>, IObservedChange<TSender, T3>, IObservedChange<TSender, T4>, IObservedChange<TSender, T5>, IObservedChange<TSender, T6>, IObservedChange<TSender, T7>, IObservedChange<TSender, T8>, TRet> selector)
         {
                         return Observable.CombineLatest(
                                     sender.ObservableForProperty(property1, false, false),
@@ -924,7 +924,7 @@ public static class WhenAnyMixin
         /// <param name="property7">The 7 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property8">The 8 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(
+        public static IObservable<TRet> WhenAnyDynamic<TSender, TRet>(
                 this TSender? sender,
                             Expression? property1,
                             Expression? property2,
@@ -934,7 +934,7 @@ public static class WhenAnyMixin
                             Expression? property6,
                             Expression? property7,
                             Expression? property8,
-                            Func<IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, TRet?> selector)
+                            Func<IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, TRet> selector)
         {
                         return Observable.CombineLatest(
                                     ReactiveNotifyPropertyChangedMixin
@@ -976,7 +976,7 @@ public static class WhenAnyMixin
         /// <param name="property8">The 8 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property9">The 9 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAnyValue<TSender, TRet, T1,T2,T3,T4,T5,T6,T7,T8,T9>(
+        public static IObservable<TRet> WhenAnyValue<TSender, TRet, T1,T2,T3,T4,T5,T6,T7,T8,T9>(
             this TSender? sender,
                         Expression<Func<TSender, T1?>> property1,
                         Expression<Func<TSender, T2?>> property2,
@@ -987,7 +987,7 @@ public static class WhenAnyMixin
                         Expression<Func<TSender, T7?>> property7,
                         Expression<Func<TSender, T8?>> property8,
                         Expression<Func<TSender, T9?>> property9,
-                        Func<T1?,T2?,T3?,T4?,T5?,T6?,T7?,T8?,T9?, TRet> selector)
+                        Func<T1,T2,T3,T4,T5,T6,T7,T8,T9, TRet> selector)
         {
             return sender.WhenAny(property1, property2, property3, property4, property5, property6, property7, property8, property9,
                                 (c1, c2, c3, c4, c5, c6, c7, c8, c9) =>
@@ -1012,7 +1012,7 @@ public static class WhenAnyMixin
         /// <param name="property8">The 8 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property9">The 9 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAny<TSender, TRet, T1,T2,T3,T4,T5,T6,T7,T8,T9>(
+        public static IObservable<TRet> WhenAny<TSender, TRet, T1,T2,T3,T4,T5,T6,T7,T8,T9>(
                 this TSender? sender,
                             Expression<Func<TSender, T1?>> property1,
                             Expression<Func<TSender, T2?>> property2,
@@ -1023,7 +1023,7 @@ public static class WhenAnyMixin
                             Expression<Func<TSender, T7?>> property7,
                             Expression<Func<TSender, T8?>> property8,
                             Expression<Func<TSender, T9?>> property9,
-                            Func<IObservedChange<TSender, T1?>, IObservedChange<TSender, T2?>, IObservedChange<TSender, T3?>, IObservedChange<TSender, T4?>, IObservedChange<TSender, T5?>, IObservedChange<TSender, T6?>, IObservedChange<TSender, T7?>, IObservedChange<TSender, T8?>, IObservedChange<TSender, T9?>, TRet?> selector)
+                            Func<IObservedChange<TSender, T1>, IObservedChange<TSender, T2>, IObservedChange<TSender, T3>, IObservedChange<TSender, T4>, IObservedChange<TSender, T5>, IObservedChange<TSender, T6>, IObservedChange<TSender, T7>, IObservedChange<TSender, T8>, IObservedChange<TSender, T9>, TRet> selector)
         {
                         return Observable.CombineLatest(
                                     sender.ObservableForProperty(property1, false, false),
@@ -1058,7 +1058,7 @@ public static class WhenAnyMixin
         /// <param name="property8">The 8 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property9">The 9 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(
+        public static IObservable<TRet> WhenAnyDynamic<TSender, TRet>(
                 this TSender? sender,
                             Expression? property1,
                             Expression? property2,
@@ -1069,7 +1069,7 @@ public static class WhenAnyMixin
                             Expression? property7,
                             Expression? property8,
                             Expression? property9,
-                            Func<IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, TRet?> selector)
+                            Func<IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, TRet> selector)
         {
                         return Observable.CombineLatest(
                                     ReactiveNotifyPropertyChangedMixin
@@ -1114,7 +1114,7 @@ public static class WhenAnyMixin
         /// <param name="property9">The 9 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property10">The 10 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAnyValue<TSender, TRet, T1,T2,T3,T4,T5,T6,T7,T8,T9,T10>(
+        public static IObservable<TRet> WhenAnyValue<TSender, TRet, T1,T2,T3,T4,T5,T6,T7,T8,T9,T10>(
             this TSender? sender,
                         Expression<Func<TSender, T1?>> property1,
                         Expression<Func<TSender, T2?>> property2,
@@ -1126,7 +1126,7 @@ public static class WhenAnyMixin
                         Expression<Func<TSender, T8?>> property8,
                         Expression<Func<TSender, T9?>> property9,
                         Expression<Func<TSender, T10?>> property10,
-                        Func<T1?,T2?,T3?,T4?,T5?,T6?,T7?,T8?,T9?,T10?, TRet> selector)
+                        Func<T1,T2,T3,T4,T5,T6,T7,T8,T9,T10, TRet> selector)
         {
             return sender.WhenAny(property1, property2, property3, property4, property5, property6, property7, property8, property9, property10,
                                 (c1, c2, c3, c4, c5, c6, c7, c8, c9, c10) =>
@@ -1152,7 +1152,7 @@ public static class WhenAnyMixin
         /// <param name="property9">The 9 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property10">The 10 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAny<TSender, TRet, T1,T2,T3,T4,T5,T6,T7,T8,T9,T10>(
+        public static IObservable<TRet> WhenAny<TSender, TRet, T1,T2,T3,T4,T5,T6,T7,T8,T9,T10>(
                 this TSender? sender,
                             Expression<Func<TSender, T1?>> property1,
                             Expression<Func<TSender, T2?>> property2,
@@ -1164,7 +1164,7 @@ public static class WhenAnyMixin
                             Expression<Func<TSender, T8?>> property8,
                             Expression<Func<TSender, T9?>> property9,
                             Expression<Func<TSender, T10?>> property10,
-                            Func<IObservedChange<TSender, T1?>, IObservedChange<TSender, T2?>, IObservedChange<TSender, T3?>, IObservedChange<TSender, T4?>, IObservedChange<TSender, T5?>, IObservedChange<TSender, T6?>, IObservedChange<TSender, T7?>, IObservedChange<TSender, T8?>, IObservedChange<TSender, T9?>, IObservedChange<TSender, T10?>, TRet?> selector)
+                            Func<IObservedChange<TSender, T1>, IObservedChange<TSender, T2>, IObservedChange<TSender, T3>, IObservedChange<TSender, T4>, IObservedChange<TSender, T5>, IObservedChange<TSender, T6>, IObservedChange<TSender, T7>, IObservedChange<TSender, T8>, IObservedChange<TSender, T9>, IObservedChange<TSender, T10>, TRet> selector)
         {
                         return Observable.CombineLatest(
                                     sender.ObservableForProperty(property1, false, false),
@@ -1201,7 +1201,7 @@ public static class WhenAnyMixin
         /// <param name="property9">The 9 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property10">The 10 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(
+        public static IObservable<TRet> WhenAnyDynamic<TSender, TRet>(
                 this TSender? sender,
                             Expression? property1,
                             Expression? property2,
@@ -1213,7 +1213,7 @@ public static class WhenAnyMixin
                             Expression? property8,
                             Expression? property9,
                             Expression? property10,
-                            Func<IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, TRet?> selector)
+                            Func<IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, TRet> selector)
         {
                         return Observable.CombineLatest(
                                     ReactiveNotifyPropertyChangedMixin
@@ -1261,7 +1261,7 @@ public static class WhenAnyMixin
         /// <param name="property10">The 10 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property11">The 11 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAnyValue<TSender, TRet, T1,T2,T3,T4,T5,T6,T7,T8,T9,T10,T11>(
+        public static IObservable<TRet> WhenAnyValue<TSender, TRet, T1,T2,T3,T4,T5,T6,T7,T8,T9,T10,T11>(
             this TSender? sender,
                         Expression<Func<TSender, T1?>> property1,
                         Expression<Func<TSender, T2?>> property2,
@@ -1274,7 +1274,7 @@ public static class WhenAnyMixin
                         Expression<Func<TSender, T9?>> property9,
                         Expression<Func<TSender, T10?>> property10,
                         Expression<Func<TSender, T11?>> property11,
-                        Func<T1?,T2?,T3?,T4?,T5?,T6?,T7?,T8?,T9?,T10?,T11?, TRet> selector)
+                        Func<T1,T2,T3,T4,T5,T6,T7,T8,T9,T10,T11, TRet> selector)
         {
             return sender.WhenAny(property1, property2, property3, property4, property5, property6, property7, property8, property9, property10, property11,
                                 (c1, c2, c3, c4, c5, c6, c7, c8, c9, c10, c11) =>
@@ -1301,7 +1301,7 @@ public static class WhenAnyMixin
         /// <param name="property10">The 10 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property11">The 11 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAny<TSender, TRet, T1,T2,T3,T4,T5,T6,T7,T8,T9,T10,T11>(
+        public static IObservable<TRet> WhenAny<TSender, TRet, T1,T2,T3,T4,T5,T6,T7,T8,T9,T10,T11>(
                 this TSender? sender,
                             Expression<Func<TSender, T1?>> property1,
                             Expression<Func<TSender, T2?>> property2,
@@ -1314,7 +1314,7 @@ public static class WhenAnyMixin
                             Expression<Func<TSender, T9?>> property9,
                             Expression<Func<TSender, T10?>> property10,
                             Expression<Func<TSender, T11?>> property11,
-                            Func<IObservedChange<TSender, T1?>, IObservedChange<TSender, T2?>, IObservedChange<TSender, T3?>, IObservedChange<TSender, T4?>, IObservedChange<TSender, T5?>, IObservedChange<TSender, T6?>, IObservedChange<TSender, T7?>, IObservedChange<TSender, T8?>, IObservedChange<TSender, T9?>, IObservedChange<TSender, T10?>, IObservedChange<TSender, T11?>, TRet?> selector)
+                            Func<IObservedChange<TSender, T1>, IObservedChange<TSender, T2>, IObservedChange<TSender, T3>, IObservedChange<TSender, T4>, IObservedChange<TSender, T5>, IObservedChange<TSender, T6>, IObservedChange<TSender, T7>, IObservedChange<TSender, T8>, IObservedChange<TSender, T9>, IObservedChange<TSender, T10>, IObservedChange<TSender, T11>, TRet> selector)
         {
                         return Observable.CombineLatest(
                                     sender.ObservableForProperty(property1, false, false),
@@ -1353,7 +1353,7 @@ public static class WhenAnyMixin
         /// <param name="property10">The 10 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property11">The 11 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(
+        public static IObservable<TRet> WhenAnyDynamic<TSender, TRet>(
                 this TSender? sender,
                             Expression? property1,
                             Expression? property2,
@@ -1366,7 +1366,7 @@ public static class WhenAnyMixin
                             Expression? property9,
                             Expression? property10,
                             Expression? property11,
-                            Func<IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, TRet?> selector)
+                            Func<IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, TRet> selector)
         {
                         return Observable.CombineLatest(
                                     ReactiveNotifyPropertyChangedMixin
@@ -1417,7 +1417,7 @@ public static class WhenAnyMixin
         /// <param name="property11">The 11 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property12">The 12 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAnyValue<TSender, TRet, T1,T2,T3,T4,T5,T6,T7,T8,T9,T10,T11,T12>(
+        public static IObservable<TRet> WhenAnyValue<TSender, TRet, T1,T2,T3,T4,T5,T6,T7,T8,T9,T10,T11,T12>(
             this TSender? sender,
                         Expression<Func<TSender, T1?>> property1,
                         Expression<Func<TSender, T2?>> property2,
@@ -1431,7 +1431,7 @@ public static class WhenAnyMixin
                         Expression<Func<TSender, T10?>> property10,
                         Expression<Func<TSender, T11?>> property11,
                         Expression<Func<TSender, T12?>> property12,
-                        Func<T1?,T2?,T3?,T4?,T5?,T6?,T7?,T8?,T9?,T10?,T11?,T12?, TRet> selector)
+                        Func<T1,T2,T3,T4,T5,T6,T7,T8,T9,T10,T11,T12, TRet> selector)
         {
             return sender.WhenAny(property1, property2, property3, property4, property5, property6, property7, property8, property9, property10, property11, property12,
                                 (c1, c2, c3, c4, c5, c6, c7, c8, c9, c10, c11, c12) =>
@@ -1459,7 +1459,7 @@ public static class WhenAnyMixin
         /// <param name="property11">The 11 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property12">The 12 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAny<TSender, TRet, T1,T2,T3,T4,T5,T6,T7,T8,T9,T10,T11,T12>(
+        public static IObservable<TRet> WhenAny<TSender, TRet, T1,T2,T3,T4,T5,T6,T7,T8,T9,T10,T11,T12>(
                 this TSender? sender,
                             Expression<Func<TSender, T1?>> property1,
                             Expression<Func<TSender, T2?>> property2,
@@ -1473,7 +1473,7 @@ public static class WhenAnyMixin
                             Expression<Func<TSender, T10?>> property10,
                             Expression<Func<TSender, T11?>> property11,
                             Expression<Func<TSender, T12?>> property12,
-                            Func<IObservedChange<TSender, T1?>, IObservedChange<TSender, T2?>, IObservedChange<TSender, T3?>, IObservedChange<TSender, T4?>, IObservedChange<TSender, T5?>, IObservedChange<TSender, T6?>, IObservedChange<TSender, T7?>, IObservedChange<TSender, T8?>, IObservedChange<TSender, T9?>, IObservedChange<TSender, T10?>, IObservedChange<TSender, T11?>, IObservedChange<TSender, T12?>, TRet?> selector)
+                            Func<IObservedChange<TSender, T1>, IObservedChange<TSender, T2>, IObservedChange<TSender, T3>, IObservedChange<TSender, T4>, IObservedChange<TSender, T5>, IObservedChange<TSender, T6>, IObservedChange<TSender, T7>, IObservedChange<TSender, T8>, IObservedChange<TSender, T9>, IObservedChange<TSender, T10>, IObservedChange<TSender, T11>, IObservedChange<TSender, T12>, TRet> selector)
         {
                         return Observable.CombineLatest(
                                     sender.ObservableForProperty(property1, false, false),
@@ -1514,7 +1514,7 @@ public static class WhenAnyMixin
         /// <param name="property11">The 11 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="property12">The 12 property chain to reference. This will be a expression pointing to a end property or field.</param>
         /// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(
+        public static IObservable<TRet> WhenAnyDynamic<TSender, TRet>(
                 this TSender? sender,
                             Expression? property1,
                             Expression? property2,
@@ -1528,7 +1528,7 @@ public static class WhenAnyMixin
                             Expression? property10,
                             Expression? property11,
                             Expression? property12,
-                            Func<IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, TRet?> selector)
+                            Func<IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, IObservedChange<TSender?, object?>, TRet> selector)
         {
                         return Observable.CombineLatest(
                                     ReactiveNotifyPropertyChangedMixin
@@ -1566,32 +1566,32 @@ public static class WhenAnyObservableMixin
         /// <summary>Observe a observable which is set to a property, and automatically subscribe to the most recent emitted value.</summary>
         /// <param name="sender">The object where the property chain starts.</param>
         /// <param name="obs1">The first observable to observe.</param>
-        public static IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, Expression<Func<TSender, IObservable<TRet>?>> obs1)
+        public static IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, Expression<Func<TSender, IObservable<TRet>?>> obs1)
             where TSender : class
         {
-            return sender!.WhenAny(obs1, x => x.Value!.EmptyIfNull())!.Switch();
+            return sender!.WhenAny(obs1, x => x.Value.EmptyIfNull()).Switch();
         }
 
         /// <summary>Monitor a property that is an observable, and subscribe to the most recent emitted value.</summary>
         /// <param name="sender">The object where the property chain starts.</param>
         /// <param name="obs1">The 1 property chain to reference which ends with an observable. This will be a expression pointing to a end property or field which must be an observable.</param>
         /// <param name="obs2">The 2 property chain to reference which ends with an observable. This will be a expression pointing to a end property or field which must be an observable.</param>
-                public static IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, Expression<Func<TSender, IObservable<TRet>?>> obs1, Expression<Func<TSender, IObservable<TRet>?>> obs2)
+                public static IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, Expression<Func<TSender, IObservable<TRet>?>> obs1, Expression<Func<TSender, IObservable<TRet>?>> obs2)
             where TSender : class
         {
-            return sender!.WhenAny(obs1, obs2, (o1, o2) => new[] {o1.Value!.EmptyIfNull(), o2.Value!.EmptyIfNull()})
-                .Select(x => x?.Merge())!.Switch();
+            return sender!.WhenAny(obs1, obs2, (o1, o2) => new[] {o1.Value.EmptyIfNull(), o2.Value.EmptyIfNull()})
+                .Select(x => x.Merge()).Switch();
         }
         /// <summary>Monitor a property that is an observable, and subscribe to the most recent emitted value.</summary>
         /// <param name="sender">The object where the property chain starts.</param>
         /// <param name="obs1">The 1 property chain to reference which ends with an observable. This will be a expression pointing to a end property or field which must be an observable.</param>
         /// <param name="obs2">The 2 property chain to reference which ends with an observable. This will be a expression pointing to a end property or field which must be an observable.</param>
         /// <param name="obs3">The 3 property chain to reference which ends with an observable. This will be a expression pointing to a end property or field which must be an observable.</param>
-                public static IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, Expression<Func<TSender, IObservable<TRet>?>> obs1, Expression<Func<TSender, IObservable<TRet>?>> obs2, Expression<Func<TSender, IObservable<TRet>?>> obs3)
+                public static IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, Expression<Func<TSender, IObservable<TRet>?>> obs1, Expression<Func<TSender, IObservable<TRet>?>> obs2, Expression<Func<TSender, IObservable<TRet>?>> obs3)
             where TSender : class
         {
-            return sender!.WhenAny(obs1, obs2, obs3, (o1, o2, o3) => new[] {o1.Value!.EmptyIfNull(), o2.Value!.EmptyIfNull(), o3.Value!.EmptyIfNull()})
-                .Select(x => x?.Merge())!.Switch();
+            return sender!.WhenAny(obs1, obs2, obs3, (o1, o2, o3) => new[] {o1.Value.EmptyIfNull(), o2.Value.EmptyIfNull(), o3.Value.EmptyIfNull()})
+                .Select(x => x.Merge()).Switch();
         }
         /// <summary>Monitor a property that is an observable, and subscribe to the most recent emitted value.</summary>
         /// <param name="sender">The object where the property chain starts.</param>
@@ -1599,11 +1599,11 @@ public static class WhenAnyObservableMixin
         /// <param name="obs2">The 2 property chain to reference which ends with an observable. This will be a expression pointing to a end property or field which must be an observable.</param>
         /// <param name="obs3">The 3 property chain to reference which ends with an observable. This will be a expression pointing to a end property or field which must be an observable.</param>
         /// <param name="obs4">The 4 property chain to reference which ends with an observable. This will be a expression pointing to a end property or field which must be an observable.</param>
-                public static IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, Expression<Func<TSender, IObservable<TRet>?>> obs1, Expression<Func<TSender, IObservable<TRet>?>> obs2, Expression<Func<TSender, IObservable<TRet>?>> obs3, Expression<Func<TSender, IObservable<TRet>?>> obs4)
+                public static IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, Expression<Func<TSender, IObservable<TRet>?>> obs1, Expression<Func<TSender, IObservable<TRet>?>> obs2, Expression<Func<TSender, IObservable<TRet>?>> obs3, Expression<Func<TSender, IObservable<TRet>?>> obs4)
             where TSender : class
         {
-            return sender!.WhenAny(obs1, obs2, obs3, obs4, (o1, o2, o3, o4) => new[] {o1.Value!.EmptyIfNull(), o2.Value!.EmptyIfNull(), o3.Value!.EmptyIfNull(), o4.Value!.EmptyIfNull()})
-                .Select(x => x?.Merge())!.Switch();
+            return sender!.WhenAny(obs1, obs2, obs3, obs4, (o1, o2, o3, o4) => new[] {o1.Value.EmptyIfNull(), o2.Value.EmptyIfNull(), o3.Value.EmptyIfNull(), o4.Value.EmptyIfNull()})
+                .Select(x => x.Merge()).Switch();
         }
         /// <summary>Monitor a property that is an observable, and subscribe to the most recent emitted value.</summary>
         /// <param name="sender">The object where the property chain starts.</param>
@@ -1612,11 +1612,11 @@ public static class WhenAnyObservableMixin
         /// <param name="obs3">The 3 property chain to reference which ends with an observable. This will be a expression pointing to a end property or field which must be an observable.</param>
         /// <param name="obs4">The 4 property chain to reference which ends with an observable. This will be a expression pointing to a end property or field which must be an observable.</param>
         /// <param name="obs5">The 5 property chain to reference which ends with an observable. This will be a expression pointing to a end property or field which must be an observable.</param>
-                public static IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, Expression<Func<TSender, IObservable<TRet>?>> obs1, Expression<Func<TSender, IObservable<TRet>?>> obs2, Expression<Func<TSender, IObservable<TRet>?>> obs3, Expression<Func<TSender, IObservable<TRet>?>> obs4, Expression<Func<TSender, IObservable<TRet>?>> obs5)
+                public static IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, Expression<Func<TSender, IObservable<TRet>?>> obs1, Expression<Func<TSender, IObservable<TRet>?>> obs2, Expression<Func<TSender, IObservable<TRet>?>> obs3, Expression<Func<TSender, IObservable<TRet>?>> obs4, Expression<Func<TSender, IObservable<TRet>?>> obs5)
             where TSender : class
         {
-            return sender!.WhenAny(obs1, obs2, obs3, obs4, obs5, (o1, o2, o3, o4, o5) => new[] {o1.Value!.EmptyIfNull(), o2.Value!.EmptyIfNull(), o3.Value!.EmptyIfNull(), o4.Value!.EmptyIfNull(), o5.Value!.EmptyIfNull()})
-                .Select(x => x?.Merge())!.Switch();
+            return sender!.WhenAny(obs1, obs2, obs3, obs4, obs5, (o1, o2, o3, o4, o5) => new[] {o1.Value.EmptyIfNull(), o2.Value.EmptyIfNull(), o3.Value.EmptyIfNull(), o4.Value.EmptyIfNull(), o5.Value.EmptyIfNull()})
+                .Select(x => x.Merge()).Switch();
         }
         /// <summary>Monitor a property that is an observable, and subscribe to the most recent emitted value.</summary>
         /// <param name="sender">The object where the property chain starts.</param>
@@ -1626,11 +1626,11 @@ public static class WhenAnyObservableMixin
         /// <param name="obs4">The 4 property chain to reference which ends with an observable. This will be a expression pointing to a end property or field which must be an observable.</param>
         /// <param name="obs5">The 5 property chain to reference which ends with an observable. This will be a expression pointing to a end property or field which must be an observable.</param>
         /// <param name="obs6">The 6 property chain to reference which ends with an observable. This will be a expression pointing to a end property or field which must be an observable.</param>
-                public static IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, Expression<Func<TSender, IObservable<TRet>?>> obs1, Expression<Func<TSender, IObservable<TRet>?>> obs2, Expression<Func<TSender, IObservable<TRet>?>> obs3, Expression<Func<TSender, IObservable<TRet>?>> obs4, Expression<Func<TSender, IObservable<TRet>?>> obs5, Expression<Func<TSender, IObservable<TRet>?>> obs6)
+                public static IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, Expression<Func<TSender, IObservable<TRet>?>> obs1, Expression<Func<TSender, IObservable<TRet>?>> obs2, Expression<Func<TSender, IObservable<TRet>?>> obs3, Expression<Func<TSender, IObservable<TRet>?>> obs4, Expression<Func<TSender, IObservable<TRet>?>> obs5, Expression<Func<TSender, IObservable<TRet>?>> obs6)
             where TSender : class
         {
-            return sender!.WhenAny(obs1, obs2, obs3, obs4, obs5, obs6, (o1, o2, o3, o4, o5, o6) => new[] {o1.Value!.EmptyIfNull(), o2.Value!.EmptyIfNull(), o3.Value!.EmptyIfNull(), o4.Value!.EmptyIfNull(), o5.Value!.EmptyIfNull(), o6.Value!.EmptyIfNull()})
-                .Select(x => x?.Merge())!.Switch();
+            return sender!.WhenAny(obs1, obs2, obs3, obs4, obs5, obs6, (o1, o2, o3, o4, o5, o6) => new[] {o1.Value.EmptyIfNull(), o2.Value.EmptyIfNull(), o3.Value.EmptyIfNull(), o4.Value.EmptyIfNull(), o5.Value.EmptyIfNull(), o6.Value.EmptyIfNull()})
+                .Select(x => x.Merge()).Switch();
         }
         /// <summary>Monitor a property that is an observable, and subscribe to the most recent emitted value.</summary>
         /// <param name="sender">The object where the property chain starts.</param>
@@ -1641,11 +1641,11 @@ public static class WhenAnyObservableMixin
         /// <param name="obs5">The 5 property chain to reference which ends with an observable. This will be a expression pointing to a end property or field which must be an observable.</param>
         /// <param name="obs6">The 6 property chain to reference which ends with an observable. This will be a expression pointing to a end property or field which must be an observable.</param>
         /// <param name="obs7">The 7 property chain to reference which ends with an observable. This will be a expression pointing to a end property or field which must be an observable.</param>
-                public static IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, Expression<Func<TSender, IObservable<TRet>?>> obs1, Expression<Func<TSender, IObservable<TRet>?>> obs2, Expression<Func<TSender, IObservable<TRet>?>> obs3, Expression<Func<TSender, IObservable<TRet>?>> obs4, Expression<Func<TSender, IObservable<TRet>?>> obs5, Expression<Func<TSender, IObservable<TRet>?>> obs6, Expression<Func<TSender, IObservable<TRet>?>> obs7)
+                public static IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, Expression<Func<TSender, IObservable<TRet>?>> obs1, Expression<Func<TSender, IObservable<TRet>?>> obs2, Expression<Func<TSender, IObservable<TRet>?>> obs3, Expression<Func<TSender, IObservable<TRet>?>> obs4, Expression<Func<TSender, IObservable<TRet>?>> obs5, Expression<Func<TSender, IObservable<TRet>?>> obs6, Expression<Func<TSender, IObservable<TRet>?>> obs7)
             where TSender : class
         {
-            return sender!.WhenAny(obs1, obs2, obs3, obs4, obs5, obs6, obs7, (o1, o2, o3, o4, o5, o6, o7) => new[] {o1.Value!.EmptyIfNull(), o2.Value!.EmptyIfNull(), o3.Value!.EmptyIfNull(), o4.Value!.EmptyIfNull(), o5.Value!.EmptyIfNull(), o6.Value!.EmptyIfNull(), o7.Value!.EmptyIfNull()})
-                .Select(x => x?.Merge())!.Switch();
+            return sender!.WhenAny(obs1, obs2, obs3, obs4, obs5, obs6, obs7, (o1, o2, o3, o4, o5, o6, o7) => new[] {o1.Value.EmptyIfNull(), o2.Value.EmptyIfNull(), o3.Value.EmptyIfNull(), o4.Value.EmptyIfNull(), o5.Value.EmptyIfNull(), o6.Value.EmptyIfNull(), o7.Value.EmptyIfNull()})
+                .Select(x => x.Merge()).Switch();
         }
         /// <summary>Monitor a property that is an observable, and subscribe to the most recent emitted value.</summary>
         /// <param name="sender">The object where the property chain starts.</param>
@@ -1657,11 +1657,11 @@ public static class WhenAnyObservableMixin
         /// <param name="obs6">The 6 property chain to reference which ends with an observable. This will be a expression pointing to a end property or field which must be an observable.</param>
         /// <param name="obs7">The 7 property chain to reference which ends with an observable. This will be a expression pointing to a end property or field which must be an observable.</param>
         /// <param name="obs8">The 8 property chain to reference which ends with an observable. This will be a expression pointing to a end property or field which must be an observable.</param>
-                public static IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, Expression<Func<TSender, IObservable<TRet>?>> obs1, Expression<Func<TSender, IObservable<TRet>?>> obs2, Expression<Func<TSender, IObservable<TRet>?>> obs3, Expression<Func<TSender, IObservable<TRet>?>> obs4, Expression<Func<TSender, IObservable<TRet>?>> obs5, Expression<Func<TSender, IObservable<TRet>?>> obs6, Expression<Func<TSender, IObservable<TRet>?>> obs7, Expression<Func<TSender, IObservable<TRet>?>> obs8)
+                public static IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, Expression<Func<TSender, IObservable<TRet>?>> obs1, Expression<Func<TSender, IObservable<TRet>?>> obs2, Expression<Func<TSender, IObservable<TRet>?>> obs3, Expression<Func<TSender, IObservable<TRet>?>> obs4, Expression<Func<TSender, IObservable<TRet>?>> obs5, Expression<Func<TSender, IObservable<TRet>?>> obs6, Expression<Func<TSender, IObservable<TRet>?>> obs7, Expression<Func<TSender, IObservable<TRet>?>> obs8)
             where TSender : class
         {
-            return sender!.WhenAny(obs1, obs2, obs3, obs4, obs5, obs6, obs7, obs8, (o1, o2, o3, o4, o5, o6, o7, o8) => new[] {o1.Value!.EmptyIfNull(), o2.Value!.EmptyIfNull(), o3.Value!.EmptyIfNull(), o4.Value!.EmptyIfNull(), o5.Value!.EmptyIfNull(), o6.Value!.EmptyIfNull(), o7.Value!.EmptyIfNull(), o8.Value!.EmptyIfNull()})
-                .Select(x => x?.Merge())!.Switch();
+            return sender!.WhenAny(obs1, obs2, obs3, obs4, obs5, obs6, obs7, obs8, (o1, o2, o3, o4, o5, o6, o7, o8) => new[] {o1.Value.EmptyIfNull(), o2.Value.EmptyIfNull(), o3.Value.EmptyIfNull(), o4.Value.EmptyIfNull(), o5.Value.EmptyIfNull(), o6.Value.EmptyIfNull(), o7.Value.EmptyIfNull(), o8.Value.EmptyIfNull()})
+                .Select(x => x.Merge()).Switch();
         }
         /// <summary>Monitor a property that is an observable, and subscribe to the most recent emitted value.</summary>
         /// <param name="sender">The object where the property chain starts.</param>
@@ -1674,11 +1674,11 @@ public static class WhenAnyObservableMixin
         /// <param name="obs7">The 7 property chain to reference which ends with an observable. This will be a expression pointing to a end property or field which must be an observable.</param>
         /// <param name="obs8">The 8 property chain to reference which ends with an observable. This will be a expression pointing to a end property or field which must be an observable.</param>
         /// <param name="obs9">The 9 property chain to reference which ends with an observable. This will be a expression pointing to a end property or field which must be an observable.</param>
-                public static IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, Expression<Func<TSender, IObservable<TRet>?>> obs1, Expression<Func<TSender, IObservable<TRet>?>> obs2, Expression<Func<TSender, IObservable<TRet>?>> obs3, Expression<Func<TSender, IObservable<TRet>?>> obs4, Expression<Func<TSender, IObservable<TRet>?>> obs5, Expression<Func<TSender, IObservable<TRet>?>> obs6, Expression<Func<TSender, IObservable<TRet>?>> obs7, Expression<Func<TSender, IObservable<TRet>?>> obs8, Expression<Func<TSender, IObservable<TRet>?>> obs9)
+                public static IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, Expression<Func<TSender, IObservable<TRet>?>> obs1, Expression<Func<TSender, IObservable<TRet>?>> obs2, Expression<Func<TSender, IObservable<TRet>?>> obs3, Expression<Func<TSender, IObservable<TRet>?>> obs4, Expression<Func<TSender, IObservable<TRet>?>> obs5, Expression<Func<TSender, IObservable<TRet>?>> obs6, Expression<Func<TSender, IObservable<TRet>?>> obs7, Expression<Func<TSender, IObservable<TRet>?>> obs8, Expression<Func<TSender, IObservable<TRet>?>> obs9)
             where TSender : class
         {
-            return sender!.WhenAny(obs1, obs2, obs3, obs4, obs5, obs6, obs7, obs8, obs9, (o1, o2, o3, o4, o5, o6, o7, o8, o9) => new[] {o1.Value!.EmptyIfNull(), o2.Value!.EmptyIfNull(), o3.Value!.EmptyIfNull(), o4.Value!.EmptyIfNull(), o5.Value!.EmptyIfNull(), o6.Value!.EmptyIfNull(), o7.Value!.EmptyIfNull(), o8.Value!.EmptyIfNull(), o9.Value!.EmptyIfNull()})
-                .Select(x => x?.Merge())!.Switch();
+            return sender!.WhenAny(obs1, obs2, obs3, obs4, obs5, obs6, obs7, obs8, obs9, (o1, o2, o3, o4, o5, o6, o7, o8, o9) => new[] {o1.Value.EmptyIfNull(), o2.Value.EmptyIfNull(), o3.Value.EmptyIfNull(), o4.Value.EmptyIfNull(), o5.Value.EmptyIfNull(), o6.Value.EmptyIfNull(), o7.Value.EmptyIfNull(), o8.Value.EmptyIfNull(), o9.Value.EmptyIfNull()})
+                .Select(x => x.Merge()).Switch();
         }
         /// <summary>Monitor a property that is an observable, and subscribe to the most recent emitted value.</summary>
         /// <param name="sender">The object where the property chain starts.</param>
@@ -1692,11 +1692,11 @@ public static class WhenAnyObservableMixin
         /// <param name="obs8">The 8 property chain to reference which ends with an observable. This will be a expression pointing to a end property or field which must be an observable.</param>
         /// <param name="obs9">The 9 property chain to reference which ends with an observable. This will be a expression pointing to a end property or field which must be an observable.</param>
         /// <param name="obs10">The 10 property chain to reference which ends with an observable. This will be a expression pointing to a end property or field which must be an observable.</param>
-                public static IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, Expression<Func<TSender, IObservable<TRet>?>> obs1, Expression<Func<TSender, IObservable<TRet>?>> obs2, Expression<Func<TSender, IObservable<TRet>?>> obs3, Expression<Func<TSender, IObservable<TRet>?>> obs4, Expression<Func<TSender, IObservable<TRet>?>> obs5, Expression<Func<TSender, IObservable<TRet>?>> obs6, Expression<Func<TSender, IObservable<TRet>?>> obs7, Expression<Func<TSender, IObservable<TRet>?>> obs8, Expression<Func<TSender, IObservable<TRet>?>> obs9, Expression<Func<TSender, IObservable<TRet>?>> obs10)
+                public static IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, Expression<Func<TSender, IObservable<TRet>?>> obs1, Expression<Func<TSender, IObservable<TRet>?>> obs2, Expression<Func<TSender, IObservable<TRet>?>> obs3, Expression<Func<TSender, IObservable<TRet>?>> obs4, Expression<Func<TSender, IObservable<TRet>?>> obs5, Expression<Func<TSender, IObservable<TRet>?>> obs6, Expression<Func<TSender, IObservable<TRet>?>> obs7, Expression<Func<TSender, IObservable<TRet>?>> obs8, Expression<Func<TSender, IObservable<TRet>?>> obs9, Expression<Func<TSender, IObservable<TRet>?>> obs10)
             where TSender : class
         {
-            return sender!.WhenAny(obs1, obs2, obs3, obs4, obs5, obs6, obs7, obs8, obs9, obs10, (o1, o2, o3, o4, o5, o6, o7, o8, o9, o10) => new[] {o1.Value!.EmptyIfNull(), o2.Value!.EmptyIfNull(), o3.Value!.EmptyIfNull(), o4.Value!.EmptyIfNull(), o5.Value!.EmptyIfNull(), o6.Value!.EmptyIfNull(), o7.Value!.EmptyIfNull(), o8.Value!.EmptyIfNull(), o9.Value!.EmptyIfNull(), o10.Value!.EmptyIfNull()})
-                .Select(x => x?.Merge())!.Switch();
+            return sender!.WhenAny(obs1, obs2, obs3, obs4, obs5, obs6, obs7, obs8, obs9, obs10, (o1, o2, o3, o4, o5, o6, o7, o8, o9, o10) => new[] {o1.Value.EmptyIfNull(), o2.Value.EmptyIfNull(), o3.Value.EmptyIfNull(), o4.Value.EmptyIfNull(), o5.Value.EmptyIfNull(), o6.Value.EmptyIfNull(), o7.Value.EmptyIfNull(), o8.Value.EmptyIfNull(), o9.Value.EmptyIfNull(), o10.Value.EmptyIfNull()})
+                .Select(x => x.Merge()).Switch();
         }
         /// <summary>Monitor a property that is an observable, and subscribe to the most recent emitted value.</summary>
         /// <param name="sender">The object where the property chain starts.</param>
@@ -1711,11 +1711,11 @@ public static class WhenAnyObservableMixin
         /// <param name="obs9">The 9 property chain to reference which ends with an observable. This will be a expression pointing to a end property or field which must be an observable.</param>
         /// <param name="obs10">The 10 property chain to reference which ends with an observable. This will be a expression pointing to a end property or field which must be an observable.</param>
         /// <param name="obs11">The 11 property chain to reference which ends with an observable. This will be a expression pointing to a end property or field which must be an observable.</param>
-                public static IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, Expression<Func<TSender, IObservable<TRet>?>> obs1, Expression<Func<TSender, IObservable<TRet>?>> obs2, Expression<Func<TSender, IObservable<TRet>?>> obs3, Expression<Func<TSender, IObservable<TRet>?>> obs4, Expression<Func<TSender, IObservable<TRet>?>> obs5, Expression<Func<TSender, IObservable<TRet>?>> obs6, Expression<Func<TSender, IObservable<TRet>?>> obs7, Expression<Func<TSender, IObservable<TRet>?>> obs8, Expression<Func<TSender, IObservable<TRet>?>> obs9, Expression<Func<TSender, IObservable<TRet>?>> obs10, Expression<Func<TSender, IObservable<TRet>?>> obs11)
+                public static IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, Expression<Func<TSender, IObservable<TRet>?>> obs1, Expression<Func<TSender, IObservable<TRet>?>> obs2, Expression<Func<TSender, IObservable<TRet>?>> obs3, Expression<Func<TSender, IObservable<TRet>?>> obs4, Expression<Func<TSender, IObservable<TRet>?>> obs5, Expression<Func<TSender, IObservable<TRet>?>> obs6, Expression<Func<TSender, IObservable<TRet>?>> obs7, Expression<Func<TSender, IObservable<TRet>?>> obs8, Expression<Func<TSender, IObservable<TRet>?>> obs9, Expression<Func<TSender, IObservable<TRet>?>> obs10, Expression<Func<TSender, IObservable<TRet>?>> obs11)
             where TSender : class
         {
-            return sender!.WhenAny(obs1, obs2, obs3, obs4, obs5, obs6, obs7, obs8, obs9, obs10, obs11, (o1, o2, o3, o4, o5, o6, o7, o8, o9, o10, o11) => new[] {o1.Value!.EmptyIfNull(), o2.Value!.EmptyIfNull(), o3.Value!.EmptyIfNull(), o4.Value!.EmptyIfNull(), o5.Value!.EmptyIfNull(), o6.Value!.EmptyIfNull(), o7.Value!.EmptyIfNull(), o8.Value!.EmptyIfNull(), o9.Value!.EmptyIfNull(), o10.Value!.EmptyIfNull(), o11.Value!.EmptyIfNull()})
-                .Select(x => x?.Merge())!.Switch();
+            return sender!.WhenAny(obs1, obs2, obs3, obs4, obs5, obs6, obs7, obs8, obs9, obs10, obs11, (o1, o2, o3, o4, o5, o6, o7, o8, o9, o10, o11) => new[] {o1.Value.EmptyIfNull(), o2.Value.EmptyIfNull(), o3.Value.EmptyIfNull(), o4.Value.EmptyIfNull(), o5.Value.EmptyIfNull(), o6.Value.EmptyIfNull(), o7.Value.EmptyIfNull(), o8.Value.EmptyIfNull(), o9.Value.EmptyIfNull(), o10.Value.EmptyIfNull(), o11.Value.EmptyIfNull()})
+                .Select(x => x.Merge()).Switch();
         }
         /// <summary>Monitor a property that is an observable, and subscribe to the most recent emitted value.</summary>
         /// <param name="sender">The object where the property chain starts.</param>
@@ -1731,11 +1731,11 @@ public static class WhenAnyObservableMixin
         /// <param name="obs10">The 10 property chain to reference which ends with an observable. This will be a expression pointing to a end property or field which must be an observable.</param>
         /// <param name="obs11">The 11 property chain to reference which ends with an observable. This will be a expression pointing to a end property or field which must be an observable.</param>
         /// <param name="obs12">The 12 property chain to reference which ends with an observable. This will be a expression pointing to a end property or field which must be an observable.</param>
-                public static IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, Expression<Func<TSender, IObservable<TRet>?>> obs1, Expression<Func<TSender, IObservable<TRet>?>> obs2, Expression<Func<TSender, IObservable<TRet>?>> obs3, Expression<Func<TSender, IObservable<TRet>?>> obs4, Expression<Func<TSender, IObservable<TRet>?>> obs5, Expression<Func<TSender, IObservable<TRet>?>> obs6, Expression<Func<TSender, IObservable<TRet>?>> obs7, Expression<Func<TSender, IObservable<TRet>?>> obs8, Expression<Func<TSender, IObservable<TRet>?>> obs9, Expression<Func<TSender, IObservable<TRet>?>> obs10, Expression<Func<TSender, IObservable<TRet>?>> obs11, Expression<Func<TSender, IObservable<TRet>?>> obs12)
+                public static IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, Expression<Func<TSender, IObservable<TRet>?>> obs1, Expression<Func<TSender, IObservable<TRet>?>> obs2, Expression<Func<TSender, IObservable<TRet>?>> obs3, Expression<Func<TSender, IObservable<TRet>?>> obs4, Expression<Func<TSender, IObservable<TRet>?>> obs5, Expression<Func<TSender, IObservable<TRet>?>> obs6, Expression<Func<TSender, IObservable<TRet>?>> obs7, Expression<Func<TSender, IObservable<TRet>?>> obs8, Expression<Func<TSender, IObservable<TRet>?>> obs9, Expression<Func<TSender, IObservable<TRet>?>> obs10, Expression<Func<TSender, IObservable<TRet>?>> obs11, Expression<Func<TSender, IObservable<TRet>?>> obs12)
             where TSender : class
         {
-            return sender!.WhenAny(obs1, obs2, obs3, obs4, obs5, obs6, obs7, obs8, obs9, obs10, obs11, obs12, (o1, o2, o3, o4, o5, o6, o7, o8, o9, o10, o11, o12) => new[] {o1.Value!.EmptyIfNull(), o2.Value!.EmptyIfNull(), o3.Value!.EmptyIfNull(), o4.Value!.EmptyIfNull(), o5.Value!.EmptyIfNull(), o6.Value!.EmptyIfNull(), o7.Value!.EmptyIfNull(), o8.Value!.EmptyIfNull(), o9.Value!.EmptyIfNull(), o10.Value!.EmptyIfNull(), o11.Value!.EmptyIfNull(), o12.Value!.EmptyIfNull()})
-                .Select(x => x?.Merge())!.Switch();
+            return sender!.WhenAny(obs1, obs2, obs3, obs4, obs5, obs6, obs7, obs8, obs9, obs10, obs11, obs12, (o1, o2, o3, o4, o5, o6, o7, o8, o9, o10, o11, o12) => new[] {o1.Value.EmptyIfNull(), o2.Value.EmptyIfNull(), o3.Value.EmptyIfNull(), o4.Value.EmptyIfNull(), o5.Value.EmptyIfNull(), o6.Value.EmptyIfNull(), o7.Value.EmptyIfNull(), o8.Value.EmptyIfNull(), o9.Value.EmptyIfNull(), o10.Value.EmptyIfNull(), o11.Value.EmptyIfNull(), o12.Value.EmptyIfNull()})
+                .Select(x => x.Merge()).Switch();
         }
 
         /// <summary>Monitor a property that is an observable, and subscribe to the most recent emitted value.</summary>
@@ -1743,13 +1743,13 @@ public static class WhenAnyObservableMixin
         /// <param name="obs1">The 1 property chain to reference.</param>
         /// <param name="obs2">The 2 property chain to reference.</param>
         /// <param name="selector">The selector which will determine the final value from the properties. This must be an observable.</param>
-        public static IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1,T2>(this TSender? sender,
+        public static IObservable<TRet> WhenAnyObservable<TSender, TRet, T1,T2>(this TSender? sender,
                             Expression<Func<TSender, IObservable<T1>?>> obs1,
                             Expression<Func<TSender, IObservable<T2>?>> obs2,
-                            Func<T1?, T2?, TRet?> selector)
+                            Func<T1?, T2?, TRet> selector)
             where TSender : class
         {
-            return sender!.WhenAny(obs1, obs2, (o1, o2) => Observable.CombineLatest(o1.Value!.EmptyIfNull(), o2.Value!.EmptyIfNull(), selector))!
+            return sender!.WhenAny(obs1, obs2, (o1, o2) => Observable.CombineLatest(o1.Value.EmptyIfNull(), o2.Value.EmptyIfNull(), selector))
                 .Switch();
         }
         /// <summary>Monitor a property that is an observable, and subscribe to the most recent emitted value.</summary>
@@ -1758,14 +1758,14 @@ public static class WhenAnyObservableMixin
         /// <param name="obs2">The 2 property chain to reference.</param>
         /// <param name="obs3">The 3 property chain to reference.</param>
         /// <param name="selector">The selector which will determine the final value from the properties. This must be an observable.</param>
-        public static IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1,T2,T3>(this TSender? sender,
+        public static IObservable<TRet> WhenAnyObservable<TSender, TRet, T1,T2,T3>(this TSender? sender,
                             Expression<Func<TSender, IObservable<T1>?>> obs1,
                             Expression<Func<TSender, IObservable<T2>?>> obs2,
                             Expression<Func<TSender, IObservable<T3>?>> obs3,
-                            Func<T1?, T2?, T3?, TRet?> selector)
+                            Func<T1?, T2?, T3?, TRet> selector)
             where TSender : class
         {
-            return sender!.WhenAny(obs1, obs2, obs3, (o1, o2, o3) => Observable.CombineLatest(o1.Value!.EmptyIfNull(), o2.Value!.EmptyIfNull(), o3.Value!.EmptyIfNull(), selector))!
+            return sender!.WhenAny(obs1, obs2, obs3, (o1, o2, o3) => Observable.CombineLatest(o1.Value.EmptyIfNull(), o2.Value.EmptyIfNull(), o3.Value.EmptyIfNull(), selector))
                 .Switch();
         }
         /// <summary>Monitor a property that is an observable, and subscribe to the most recent emitted value.</summary>
@@ -1775,15 +1775,15 @@ public static class WhenAnyObservableMixin
         /// <param name="obs3">The 3 property chain to reference.</param>
         /// <param name="obs4">The 4 property chain to reference.</param>
         /// <param name="selector">The selector which will determine the final value from the properties. This must be an observable.</param>
-        public static IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1,T2,T3,T4>(this TSender? sender,
+        public static IObservable<TRet> WhenAnyObservable<TSender, TRet, T1,T2,T3,T4>(this TSender? sender,
                             Expression<Func<TSender, IObservable<T1>?>> obs1,
                             Expression<Func<TSender, IObservable<T2>?>> obs2,
                             Expression<Func<TSender, IObservable<T3>?>> obs3,
                             Expression<Func<TSender, IObservable<T4>?>> obs4,
-                            Func<T1?, T2?, T3?, T4?, TRet?> selector)
+                            Func<T1?, T2?, T3?, T4?, TRet> selector)
             where TSender : class
         {
-            return sender!.WhenAny(obs1, obs2, obs3, obs4, (o1, o2, o3, o4) => Observable.CombineLatest(o1.Value!.EmptyIfNull(), o2.Value!.EmptyIfNull(), o3.Value!.EmptyIfNull(), o4.Value!.EmptyIfNull(), selector))!
+            return sender!.WhenAny(obs1, obs2, obs3, obs4, (o1, o2, o3, o4) => Observable.CombineLatest(o1.Value.EmptyIfNull(), o2.Value.EmptyIfNull(), o3.Value.EmptyIfNull(), o4.Value.EmptyIfNull(), selector))
                 .Switch();
         }
         /// <summary>Monitor a property that is an observable, and subscribe to the most recent emitted value.</summary>
@@ -1794,16 +1794,16 @@ public static class WhenAnyObservableMixin
         /// <param name="obs4">The 4 property chain to reference.</param>
         /// <param name="obs5">The 5 property chain to reference.</param>
         /// <param name="selector">The selector which will determine the final value from the properties. This must be an observable.</param>
-        public static IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1,T2,T3,T4,T5>(this TSender? sender,
+        public static IObservable<TRet> WhenAnyObservable<TSender, TRet, T1,T2,T3,T4,T5>(this TSender? sender,
                             Expression<Func<TSender, IObservable<T1>?>> obs1,
                             Expression<Func<TSender, IObservable<T2>?>> obs2,
                             Expression<Func<TSender, IObservable<T3>?>> obs3,
                             Expression<Func<TSender, IObservable<T4>?>> obs4,
                             Expression<Func<TSender, IObservable<T5>?>> obs5,
-                            Func<T1?, T2?, T3?, T4?, T5?, TRet?> selector)
+                            Func<T1?, T2?, T3?, T4?, T5?, TRet> selector)
             where TSender : class
         {
-            return sender!.WhenAny(obs1, obs2, obs3, obs4, obs5, (o1, o2, o3, o4, o5) => Observable.CombineLatest(o1.Value!.EmptyIfNull(), o2.Value!.EmptyIfNull(), o3.Value!.EmptyIfNull(), o4.Value!.EmptyIfNull(), o5.Value!.EmptyIfNull(), selector))!
+            return sender!.WhenAny(obs1, obs2, obs3, obs4, obs5, (o1, o2, o3, o4, o5) => Observable.CombineLatest(o1.Value.EmptyIfNull(), o2.Value.EmptyIfNull(), o3.Value.EmptyIfNull(), o4.Value.EmptyIfNull(), o5.Value.EmptyIfNull(), selector))
                 .Switch();
         }
         /// <summary>Monitor a property that is an observable, and subscribe to the most recent emitted value.</summary>
@@ -1815,17 +1815,17 @@ public static class WhenAnyObservableMixin
         /// <param name="obs5">The 5 property chain to reference.</param>
         /// <param name="obs6">The 6 property chain to reference.</param>
         /// <param name="selector">The selector which will determine the final value from the properties. This must be an observable.</param>
-        public static IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1,T2,T3,T4,T5,T6>(this TSender? sender,
+        public static IObservable<TRet> WhenAnyObservable<TSender, TRet, T1,T2,T3,T4,T5,T6>(this TSender? sender,
                             Expression<Func<TSender, IObservable<T1>?>> obs1,
                             Expression<Func<TSender, IObservable<T2>?>> obs2,
                             Expression<Func<TSender, IObservable<T3>?>> obs3,
                             Expression<Func<TSender, IObservable<T4>?>> obs4,
                             Expression<Func<TSender, IObservable<T5>?>> obs5,
                             Expression<Func<TSender, IObservable<T6>?>> obs6,
-                            Func<T1?, T2?, T3?, T4?, T5?, T6?, TRet?> selector)
+                            Func<T1?, T2?, T3?, T4?, T5?, T6?, TRet> selector)
             where TSender : class
         {
-            return sender!.WhenAny(obs1, obs2, obs3, obs4, obs5, obs6, (o1, o2, o3, o4, o5, o6) => Observable.CombineLatest(o1.Value!.EmptyIfNull(), o2.Value!.EmptyIfNull(), o3.Value!.EmptyIfNull(), o4.Value!.EmptyIfNull(), o5.Value!.EmptyIfNull(), o6.Value!.EmptyIfNull(), selector))!
+            return sender!.WhenAny(obs1, obs2, obs3, obs4, obs5, obs6, (o1, o2, o3, o4, o5, o6) => Observable.CombineLatest(o1.Value.EmptyIfNull(), o2.Value.EmptyIfNull(), o3.Value.EmptyIfNull(), o4.Value.EmptyIfNull(), o5.Value.EmptyIfNull(), o6.Value.EmptyIfNull(), selector))
                 .Switch();
         }
         /// <summary>Monitor a property that is an observable, and subscribe to the most recent emitted value.</summary>
@@ -1838,7 +1838,7 @@ public static class WhenAnyObservableMixin
         /// <param name="obs6">The 6 property chain to reference.</param>
         /// <param name="obs7">The 7 property chain to reference.</param>
         /// <param name="selector">The selector which will determine the final value from the properties. This must be an observable.</param>
-        public static IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1,T2,T3,T4,T5,T6,T7>(this TSender? sender,
+        public static IObservable<TRet> WhenAnyObservable<TSender, TRet, T1,T2,T3,T4,T5,T6,T7>(this TSender? sender,
                             Expression<Func<TSender, IObservable<T1>?>> obs1,
                             Expression<Func<TSender, IObservable<T2>?>> obs2,
                             Expression<Func<TSender, IObservable<T3>?>> obs3,
@@ -1846,10 +1846,10 @@ public static class WhenAnyObservableMixin
                             Expression<Func<TSender, IObservable<T5>?>> obs5,
                             Expression<Func<TSender, IObservable<T6>?>> obs6,
                             Expression<Func<TSender, IObservable<T7>?>> obs7,
-                            Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, TRet?> selector)
+                            Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, TRet> selector)
             where TSender : class
         {
-            return sender!.WhenAny(obs1, obs2, obs3, obs4, obs5, obs6, obs7, (o1, o2, o3, o4, o5, o6, o7) => Observable.CombineLatest(o1.Value!.EmptyIfNull(), o2.Value!.EmptyIfNull(), o3.Value!.EmptyIfNull(), o4.Value!.EmptyIfNull(), o5.Value!.EmptyIfNull(), o6.Value!.EmptyIfNull(), o7.Value!.EmptyIfNull(), selector))!
+            return sender!.WhenAny(obs1, obs2, obs3, obs4, obs5, obs6, obs7, (o1, o2, o3, o4, o5, o6, o7) => Observable.CombineLatest(o1.Value.EmptyIfNull(), o2.Value.EmptyIfNull(), o3.Value.EmptyIfNull(), o4.Value.EmptyIfNull(), o5.Value.EmptyIfNull(), o6.Value.EmptyIfNull(), o7.Value.EmptyIfNull(), selector))
                 .Switch();
         }
         /// <summary>Monitor a property that is an observable, and subscribe to the most recent emitted value.</summary>
@@ -1863,7 +1863,7 @@ public static class WhenAnyObservableMixin
         /// <param name="obs7">The 7 property chain to reference.</param>
         /// <param name="obs8">The 8 property chain to reference.</param>
         /// <param name="selector">The selector which will determine the final value from the properties. This must be an observable.</param>
-        public static IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1,T2,T3,T4,T5,T6,T7,T8>(this TSender? sender,
+        public static IObservable<TRet> WhenAnyObservable<TSender, TRet, T1,T2,T3,T4,T5,T6,T7,T8>(this TSender? sender,
                             Expression<Func<TSender, IObservable<T1>?>> obs1,
                             Expression<Func<TSender, IObservable<T2>?>> obs2,
                             Expression<Func<TSender, IObservable<T3>?>> obs3,
@@ -1872,10 +1872,10 @@ public static class WhenAnyObservableMixin
                             Expression<Func<TSender, IObservable<T6>?>> obs6,
                             Expression<Func<TSender, IObservable<T7>?>> obs7,
                             Expression<Func<TSender, IObservable<T8>?>> obs8,
-                            Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, TRet?> selector)
+                            Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, TRet> selector)
             where TSender : class
         {
-            return sender!.WhenAny(obs1, obs2, obs3, obs4, obs5, obs6, obs7, obs8, (o1, o2, o3, o4, o5, o6, o7, o8) => Observable.CombineLatest(o1.Value!.EmptyIfNull(), o2.Value!.EmptyIfNull(), o3.Value!.EmptyIfNull(), o4.Value!.EmptyIfNull(), o5.Value!.EmptyIfNull(), o6.Value!.EmptyIfNull(), o7.Value!.EmptyIfNull(), o8.Value!.EmptyIfNull(), selector))!
+            return sender!.WhenAny(obs1, obs2, obs3, obs4, obs5, obs6, obs7, obs8, (o1, o2, o3, o4, o5, o6, o7, o8) => Observable.CombineLatest(o1.Value.EmptyIfNull(), o2.Value.EmptyIfNull(), o3.Value.EmptyIfNull(), o4.Value.EmptyIfNull(), o5.Value.EmptyIfNull(), o6.Value.EmptyIfNull(), o7.Value.EmptyIfNull(), o8.Value.EmptyIfNull(), selector))
                 .Switch();
         }
         /// <summary>Monitor a property that is an observable, and subscribe to the most recent emitted value.</summary>
@@ -1890,7 +1890,7 @@ public static class WhenAnyObservableMixin
         /// <param name="obs8">The 8 property chain to reference.</param>
         /// <param name="obs9">The 9 property chain to reference.</param>
         /// <param name="selector">The selector which will determine the final value from the properties. This must be an observable.</param>
-        public static IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1,T2,T3,T4,T5,T6,T7,T8,T9>(this TSender? sender,
+        public static IObservable<TRet> WhenAnyObservable<TSender, TRet, T1,T2,T3,T4,T5,T6,T7,T8,T9>(this TSender? sender,
                             Expression<Func<TSender, IObservable<T1>?>> obs1,
                             Expression<Func<TSender, IObservable<T2>?>> obs2,
                             Expression<Func<TSender, IObservable<T3>?>> obs3,
@@ -1900,10 +1900,10 @@ public static class WhenAnyObservableMixin
                             Expression<Func<TSender, IObservable<T7>?>> obs7,
                             Expression<Func<TSender, IObservable<T8>?>> obs8,
                             Expression<Func<TSender, IObservable<T9>?>> obs9,
-                            Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, TRet?> selector)
+                            Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, TRet> selector)
             where TSender : class
         {
-            return sender!.WhenAny(obs1, obs2, obs3, obs4, obs5, obs6, obs7, obs8, obs9, (o1, o2, o3, o4, o5, o6, o7, o8, o9) => Observable.CombineLatest(o1.Value!.EmptyIfNull(), o2.Value!.EmptyIfNull(), o3.Value!.EmptyIfNull(), o4.Value!.EmptyIfNull(), o5.Value!.EmptyIfNull(), o6.Value!.EmptyIfNull(), o7.Value!.EmptyIfNull(), o8.Value!.EmptyIfNull(), o9.Value!.EmptyIfNull(), selector))!
+            return sender!.WhenAny(obs1, obs2, obs3, obs4, obs5, obs6, obs7, obs8, obs9, (o1, o2, o3, o4, o5, o6, o7, o8, o9) => Observable.CombineLatest(o1.Value.EmptyIfNull(), o2.Value.EmptyIfNull(), o3.Value.EmptyIfNull(), o4.Value.EmptyIfNull(), o5.Value.EmptyIfNull(), o6.Value.EmptyIfNull(), o7.Value.EmptyIfNull(), o8.Value.EmptyIfNull(), o9.Value.EmptyIfNull(), selector))
                 .Switch();
         }
         /// <summary>Monitor a property that is an observable, and subscribe to the most recent emitted value.</summary>
@@ -1919,7 +1919,7 @@ public static class WhenAnyObservableMixin
         /// <param name="obs9">The 9 property chain to reference.</param>
         /// <param name="obs10">The 10 property chain to reference.</param>
         /// <param name="selector">The selector which will determine the final value from the properties. This must be an observable.</param>
-        public static IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1,T2,T3,T4,T5,T6,T7,T8,T9,T10>(this TSender? sender,
+        public static IObservable<TRet> WhenAnyObservable<TSender, TRet, T1,T2,T3,T4,T5,T6,T7,T8,T9,T10>(this TSender? sender,
                             Expression<Func<TSender, IObservable<T1>?>> obs1,
                             Expression<Func<TSender, IObservable<T2>?>> obs2,
                             Expression<Func<TSender, IObservable<T3>?>> obs3,
@@ -1930,10 +1930,10 @@ public static class WhenAnyObservableMixin
                             Expression<Func<TSender, IObservable<T8>?>> obs8,
                             Expression<Func<TSender, IObservable<T9>?>> obs9,
                             Expression<Func<TSender, IObservable<T10>?>> obs10,
-                            Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, TRet?> selector)
+                            Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, TRet> selector)
             where TSender : class
         {
-            return sender!.WhenAny(obs1, obs2, obs3, obs4, obs5, obs6, obs7, obs8, obs9, obs10, (o1, o2, o3, o4, o5, o6, o7, o8, o9, o10) => Observable.CombineLatest(o1.Value!.EmptyIfNull(), o2.Value!.EmptyIfNull(), o3.Value!.EmptyIfNull(), o4.Value!.EmptyIfNull(), o5.Value!.EmptyIfNull(), o6.Value!.EmptyIfNull(), o7.Value!.EmptyIfNull(), o8.Value!.EmptyIfNull(), o9.Value!.EmptyIfNull(), o10.Value!.EmptyIfNull(), selector))!
+            return sender!.WhenAny(obs1, obs2, obs3, obs4, obs5, obs6, obs7, obs8, obs9, obs10, (o1, o2, o3, o4, o5, o6, o7, o8, o9, o10) => Observable.CombineLatest(o1.Value.EmptyIfNull(), o2.Value.EmptyIfNull(), o3.Value.EmptyIfNull(), o4.Value.EmptyIfNull(), o5.Value.EmptyIfNull(), o6.Value.EmptyIfNull(), o7.Value.EmptyIfNull(), o8.Value.EmptyIfNull(), o9.Value.EmptyIfNull(), o10.Value.EmptyIfNull(), selector))
                 .Switch();
         }
         /// <summary>Monitor a property that is an observable, and subscribe to the most recent emitted value.</summary>
@@ -1950,7 +1950,7 @@ public static class WhenAnyObservableMixin
         /// <param name="obs10">The 10 property chain to reference.</param>
         /// <param name="obs11">The 11 property chain to reference.</param>
         /// <param name="selector">The selector which will determine the final value from the properties. This must be an observable.</param>
-        public static IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1,T2,T3,T4,T5,T6,T7,T8,T9,T10,T11>(this TSender? sender,
+        public static IObservable<TRet> WhenAnyObservable<TSender, TRet, T1,T2,T3,T4,T5,T6,T7,T8,T9,T10,T11>(this TSender? sender,
                             Expression<Func<TSender, IObservable<T1>?>> obs1,
                             Expression<Func<TSender, IObservable<T2>?>> obs2,
                             Expression<Func<TSender, IObservable<T3>?>> obs3,
@@ -1962,10 +1962,10 @@ public static class WhenAnyObservableMixin
                             Expression<Func<TSender, IObservable<T9>?>> obs9,
                             Expression<Func<TSender, IObservable<T10>?>> obs10,
                             Expression<Func<TSender, IObservable<T11>?>> obs11,
-                            Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, T11?, TRet?> selector)
+                            Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, T11?, TRet> selector)
             where TSender : class
         {
-            return sender!.WhenAny(obs1, obs2, obs3, obs4, obs5, obs6, obs7, obs8, obs9, obs10, obs11, (o1, o2, o3, o4, o5, o6, o7, o8, o9, o10, o11) => Observable.CombineLatest(o1.Value!.EmptyIfNull(), o2.Value!.EmptyIfNull(), o3.Value!.EmptyIfNull(), o4.Value!.EmptyIfNull(), o5.Value!.EmptyIfNull(), o6.Value!.EmptyIfNull(), o7.Value!.EmptyIfNull(), o8.Value!.EmptyIfNull(), o9.Value!.EmptyIfNull(), o10.Value!.EmptyIfNull(), o11.Value!.EmptyIfNull(), selector))!
+            return sender!.WhenAny(obs1, obs2, obs3, obs4, obs5, obs6, obs7, obs8, obs9, obs10, obs11, (o1, o2, o3, o4, o5, o6, o7, o8, o9, o10, o11) => Observable.CombineLatest(o1.Value.EmptyIfNull(), o2.Value.EmptyIfNull(), o3.Value.EmptyIfNull(), o4.Value.EmptyIfNull(), o5.Value.EmptyIfNull(), o6.Value.EmptyIfNull(), o7.Value.EmptyIfNull(), o8.Value.EmptyIfNull(), o9.Value.EmptyIfNull(), o10.Value.EmptyIfNull(), o11.Value.EmptyIfNull(), selector))
                 .Switch();
         }
         /// <summary>Monitor a property that is an observable, and subscribe to the most recent emitted value.</summary>
@@ -1983,7 +1983,7 @@ public static class WhenAnyObservableMixin
         /// <param name="obs11">The 11 property chain to reference.</param>
         /// <param name="obs12">The 12 property chain to reference.</param>
         /// <param name="selector">The selector which will determine the final value from the properties. This must be an observable.</param>
-        public static IObservable<TRet?> WhenAnyObservable<TSender, TRet, T1,T2,T3,T4,T5,T6,T7,T8,T9,T10,T11,T12>(this TSender? sender,
+        public static IObservable<TRet> WhenAnyObservable<TSender, TRet, T1,T2,T3,T4,T5,T6,T7,T8,T9,T10,T11,T12>(this TSender? sender,
                             Expression<Func<TSender, IObservable<T1>?>> obs1,
                             Expression<Func<TSender, IObservable<T2>?>> obs2,
                             Expression<Func<TSender, IObservable<T3>?>> obs3,
@@ -1996,10 +1996,10 @@ public static class WhenAnyObservableMixin
                             Expression<Func<TSender, IObservable<T10>?>> obs10,
                             Expression<Func<TSender, IObservable<T11>?>> obs11,
                             Expression<Func<TSender, IObservable<T12>?>> obs12,
-                            Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, T11?, T12?, TRet?> selector)
+                            Func<T1?, T2?, T3?, T4?, T5?, T6?, T7?, T8?, T9?, T10?, T11?, T12?, TRet> selector)
             where TSender : class
         {
-            return sender!.WhenAny(obs1, obs2, obs3, obs4, obs5, obs6, obs7, obs8, obs9, obs10, obs11, obs12, (o1, o2, o3, o4, o5, o6, o7, o8, o9, o10, o11, o12) => Observable.CombineLatest(o1.Value!.EmptyIfNull(), o2.Value!.EmptyIfNull(), o3.Value!.EmptyIfNull(), o4.Value!.EmptyIfNull(), o5.Value!.EmptyIfNull(), o6.Value!.EmptyIfNull(), o7.Value!.EmptyIfNull(), o8.Value!.EmptyIfNull(), o9.Value!.EmptyIfNull(), o10.Value!.EmptyIfNull(), o11.Value!.EmptyIfNull(), o12.Value!.EmptyIfNull(), selector))!
+            return sender!.WhenAny(obs1, obs2, obs3, obs4, obs5, obs6, obs7, obs8, obs9, obs10, obs11, obs12, (o1, o2, o3, o4, o5, o6, o7, o8, o9, o10, o11, o12) => Observable.CombineLatest(o1.Value.EmptyIfNull(), o2.Value.EmptyIfNull(), o3.Value.EmptyIfNull(), o4.Value.EmptyIfNull(), o5.Value.EmptyIfNull(), o6.Value.EmptyIfNull(), o7.Value.EmptyIfNull(), o8.Value.EmptyIfNull(), o9.Value.EmptyIfNull(), o10.Value.EmptyIfNull(), o11.Value.EmptyIfNull(), o12.Value.EmptyIfNull(), selector))
                 .Switch();
         }
 }
diff --git a/src/ReactiveUI/VariadicTemplates.tt b/src/ReactiveUI/VariadicTemplates.tt
index 57c87ab51d..670e9c7957 100644
--- a/src/ReactiveUI/VariadicTemplates.tt
+++ b/src/ReactiveUI/VariadicTemplates.tt
@@ -44,15 +44,15 @@ namespace ReactiveUI
         /// </summary>
         /// <param name="sender">The object where the property chain starts.</param>
         /// <param name="property1">The first property chain to reference. This will be a expression pointing to a end property or field.</param>
-        public static IObservable<TRet?> WhenAnyValue<TSender, TRet>(
+        public static IObservable<TRet> WhenAnyValue<TSender, TRet>(
             this TSender? sender,
             Expression<Func<TSender, TRet?>> property1)
         {
-            return sender.WhenAny(property1, (IObservedChange<TSender, TRet?> c1) => c1.Value);
+            return sender.WhenAny(property1, (IObservedChange<TSender, TRet> c1) => c1.Value);
         }
 
         <# for(int length=1; length <= maxFuncLength; length++) { #>
-        <# var templParams = Enumerable.Range(1, length).Select(x => "T" + x.ToString() + "?"); #>
+        <# var templParams = Enumerable.Range(1, length).Select(x => "T" + x.ToString()); #>
         <# var templParamsDec = Enumerable.Range(1, length).Select(x => "T" + x.ToString()); #>
         <# string selectorTypeParams = String.Join(", ", templParams.Select(x => String.Format("IObservedChange<TSender, {0}>", x))); #>
         <# string valuePropertyParams = String.Join(", ", Enumerable.Range(1, length).Select(x => String.Format("property{0}", x))); #>
@@ -95,7 +95,7 @@ namespace ReactiveUI
         <# for(int i=1; i <= length; i++) { #>
 /// <param name="property<#=i#>">The <#=i#> property chain to reference. This will be a expression pointing to a end property or field.</param>
         <# } #>/// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAnyValue<TSender, TRet, <#= String.Join(",", templParamsDec) #>>(
+        public static IObservable<TRet> WhenAnyValue<TSender, TRet, <#= String.Join(",", templParamsDec) #>>(
             this TSender? sender,
             <# for(int i=1; i <= length; i++) { #>
             Expression<Func<TSender, T<#=i#>?>> property<#=i#>,
@@ -118,12 +118,12 @@ namespace ReactiveUI
         <# for(int i=1; i <= length; i++) { #>
 /// <param name="property<#=i#>">The <#=i#> property chain to reference. This will be a expression pointing to a end property or field.</param>
         <# } #>/// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAny<TSender, TRet, <#= String.Join(",", templParamsDec) #>>(
+        public static IObservable<TRet> WhenAny<TSender, TRet, <#= String.Join(",", templParamsDec) #>>(
                 this TSender? sender,
             <# for(int i=1; i <= length; i++) { #>
                 Expression<Func<TSender, T<#=i#>?>> property<#=i#>,
             <# } #>
-                Func<<#= selectorTypeParams #>, TRet?> selector)
+                Func<<#= selectorTypeParams #>, TRet> selector)
         {
             <# if (length == 1){ #>
                 return sender.ObservableForProperty(property<#=1#>, false, false).Select(selector);
@@ -149,12 +149,12 @@ namespace ReactiveUI
         <# for(int i=1; i <= length; i++) { #>
 /// <param name="property<#=i#>">The <#=i#> property chain to reference. This will be a expression pointing to a end property or field.</param>
         <# } #>/// <param name="selector">The selector which will determine the final value from the properties.</param>
-        public static IObservable<TRet?> WhenAnyDynamic<TSender, TRet>(
+        public static IObservable<TRet> WhenAnyDynamic<TSender, TRet>(
                 this TSender? sender,
             <# for(int i=1; i <= length; i++) { #>
                 Expression? property<#=i#>,
             <# } #>
-                Func<<#= dynamicSelectorTypeParams #>, TRet?> selector)
+                Func<<#= dynamicSelectorTypeParams #>, TRet> selector)
         {
             <# if (length == 1){ #>
                 return ReactiveNotifyPropertyChangedMixin
@@ -178,10 +178,10 @@ namespace ReactiveUI
         /// <summary>Observe a observable which is set to a property, and automatically subscribe to the most recent emitted value.</summary>
         /// <param name="sender">The object where the property chain starts.</param>
         /// <param name="obs1">The first observable to observe.</param>
-        public static IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, Expression<Func<TSender, IObservable<TRet>?>> obs1)
+        public static IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, Expression<Func<TSender, IObservable<TRet>?>> obs1)
             where TSender : class
         {
-            return sender!.WhenAny(obs1, x => x.Value!.EmptyIfNull())!.Switch();
+            return sender!.WhenAny(obs1, x => x.Value.EmptyIfNull()).Switch();
         }
 
 <# for(int length=2; length <= maxFuncLength; length++) { #>
@@ -192,12 +192,12 @@ namespace ReactiveUI
         <# } #>
 <# string paramsStr = String.Join(", ", Enumerable.Range(1, length).Select(x => "Expression<Func<TSender, IObservable<TRet>?>> obs" + x.ToString())); #>
 <# string varsStr = String.Join(", ", Enumerable.Range(1, length).Select(x => "obs" + x.ToString())); #>
-<# string valsStr = String.Join(", ", Enumerable.Range(1, length).Select(x => "o" + x.ToString() + ".Value!.EmptyIfNull()")); #>
-        public static IObservable<TRet?> WhenAnyObservable<TSender, TRet>(this TSender? sender, <#= paramsStr #>)
+<# string valsStr = String.Join(", ", Enumerable.Range(1, length).Select(x => "o" + x.ToString() + ".Value.EmptyIfNull()")); #>
+        public static IObservable<TRet> WhenAnyObservable<TSender, TRet>(this TSender? sender, <#= paramsStr #>)
             where TSender : class
         {
             return sender!.WhenAny(<#= varsStr #>, (<#=varsStr.Replace("obs", "o")#>) => new[] {<#= valsStr #>})
-                .Select(x => x?.Merge())!.Switch();
+                .Select(x => x.Merge()).Switch();
         }
 <# } #>
 
@@ -210,16 +210,16 @@ namespace ReactiveUI
 <# var templParams = Enumerable.Range(1, length).Select(x => "T" + x.ToString() + "?"); #>
 <# var templParamsDec = Enumerable.Range(1, length).Select(x => "T" + x.ToString()); #>
 <# string varsStr = String.Join(", ", Enumerable.Range(1, length).Select(x => "obs" + x.ToString())); #>
-<# string valsStr = String.Join(", ", Enumerable.Range(1, length).Select(x => "o" + x.ToString() + ".Value!.EmptyIfNull()")); #>
+<# string valsStr = String.Join(", ", Enumerable.Range(1, length).Select(x => "o" + x.ToString() + ".Value.EmptyIfNull()")); #>
 <# string selectorTypeParams = String.Join(", ", templParams); #>
-        public static IObservable<TRet?> WhenAnyObservable<TSender, TRet, <#= String.Join(",", templParamsDec) #>>(this TSender? sender,
+        public static IObservable<TRet> WhenAnyObservable<TSender, TRet, <#= String.Join(",", templParamsDec) #>>(this TSender? sender,
             <# for(int i=1; i <= length; i++) { #>
                 Expression<Func<TSender, IObservable<T<#=i#>>?>> obs<#=i#>,
             <# } #>
-                Func<<#= selectorTypeParams #>, TRet?> selector)
+                Func<<#= selectorTypeParams #>, TRet> selector)
             where TSender : class
         {
-            return sender!.WhenAny(<#= varsStr #>, (<#=varsStr.Replace("obs", "o")#>) => Observable.CombineLatest(<#= valsStr #>, selector))!
+            return sender!.WhenAny(<#= varsStr #>, (<#=varsStr.Replace("obs", "o")#>) => Observable.CombineLatest(<#= valsStr #>, selector))
                 .Switch();
         }
 <# } #>

From b2e9db96b9c70a426d178027b047b9b7f1a2efa7 Mon Sep 17 00:00:00 2001
From: "dependabot[bot]" <49699333+dependabot[bot]@users.noreply.github.com>
Date: Mon, 28 Jun 2021 08:01:56 +0100
Subject: [PATCH 2/2] build(deps): bump Nerdbank.GitVersioning from 3.4.216 to
 3.4.220 in /src (#2810)

Bumps [Nerdbank.GitVersioning](https://github.com/dotnet/Nerdbank.GitVersioning) from 3.4.216 to 3.4.220.
- [Release notes](https://github.com/dotnet/Nerdbank.GitVersioning/releases)
- [Commits](https://github.com/dotnet/Nerdbank.GitVersioning/compare/v3.4.216...v3.4.220)

---
updated-dependencies:
- dependency-name: Nerdbank.GitVersioning
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
---
 src/Directory.build.props | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Directory.build.props b/src/Directory.build.props
index e22234fc44..3cadcab715 100644
--- a/src/Directory.build.props
+++ b/src/Directory.build.props
@@ -59,7 +59,7 @@
   </ItemGroup>
 
   <ItemGroup>	
-    <PackageReference Include="Nerdbank.GitVersioning" Version="3.4.216" PrivateAssets="all" />	
+    <PackageReference Include="Nerdbank.GitVersioning" Version="3.4.220" PrivateAssets="all" />	
   </ItemGroup>
 
   <ItemGroup>