diff --git a/README.md b/README.md
index 9b4d23fa8..d1c6de3f3 100755
--- a/README.md
+++ b/README.md
@@ -35,12 +35,17 @@ Keep in mind to enable the correct Docker engine on Windows host systems to matc
 - `WithCleanUp` removes a stopped container automatically.
 - `WithDockerEndpoint` sets the Docker API endpoint e. g. `-H tcp://0.0.0.0:2376`.
 - `WithRegistryAuthentication` basic authentication against a private Docker registry.
-- `WithOutputConsumer` redirects `stdout` and `stderr` to capture the Testcontainer output.
-- `WithWaitStrategy` sets the wait strategy to complete the Testcontainer start and indicates when it is ready.
-- `WithStartupCallback` sets the startup callback to invoke after the Testcontainer start.
+- `WithOutputConsumer` redirects `stdout` and `stderr` to capture the Testcontainers output.
+- `WithWaitStrategy` sets the wait strategy to complete the Testcontainers start and indicates when it is ready.
+- `WithStartupCallback` sets the startup callback to invoke after the Testcontainers start.
+- `WithResourceReaperSessionId` sets the resource reaper session id.
 - `WithDockerfileDirectory` builds a Docker image based on a Dockerfile (`ImageFromDockerfileBuilder`).
 - `WithDeleteIfExists` removes the Docker image before it is rebuilt (`ImageFromDockerfileBuilder`).
 
+## Resource Reaper
+
+Testcontainers assigns each Docker resource a Resource Reaper session id. After the tests are finished, [Ryuk][moby-ryuk] will take care of remaining Docker resources and removes them. You can change the Resource Reaper session and group Docker resources together with `WithResourceReaperSessionId`. Right now, only Linux containers are supported.
+
 ## Pre-configured containers
 
 The pre-configured Testcontainers below are supported. Further examples can be found in [TestcontainersContainerTest][1] as well as in [database][2] or [message broker][3] tests.
@@ -67,9 +72,9 @@ var testcontainersBuilder = new TestcontainersBuilder<TestcontainersContainer>()
   .WithPortBinding(80)
   .WithWaitStrategy(Wait.ForUnixContainer().UntilPortIsAvailable(80));
 
-await using (var testcontainer = testcontainersBuilder.Build())
+await using (var testcontainers = testcontainersBuilder.Build())
 {
-  await testcontainer.StartAsync();
+  await testcontainers.StartAsync();
   var request = WebRequest.Create("http://localhost:80");
 }
 ```
@@ -84,13 +89,13 @@ var testcontainersBuilder = new TestcontainersBuilder<TestcontainersContainer>()
   .WithCommand("/bin/bash", "-c", "hostname > /tmp/hostname")
   .WithWaitStrategy(Wait.ForUnixContainer().UntilFileExists("/tmp/hostname"));
 
-await using (var testcontainer = testcontainersBuilder.Build())
+await using (var testcontainers = testcontainersBuilder.Build())
 {
-  await testcontainer.StartAsync();
+  await testcontainers.StartAsync();
 }
 ```
 
-Here is an example of a pre-configured Testcontainer. In the example, Testcontainers starts a PostgreSQL database and executes a SQL query.
+Here is an example of a pre-configured Testcontainers. In the example, Testcontainers starts a PostgreSQL database and executes a SQL query.
 
 ```csharp
 var testcontainersBuilder = new TestcontainersBuilder<PostgreSqlTestcontainer>()
@@ -101,11 +106,11 @@ var testcontainersBuilder = new TestcontainersBuilder<PostgreSqlTestcontainer>()
     Password = "postgres",
   });
 
-await using (var testcontainer = testcontainersBuilder.Build())
+await using (var testcontainers = testcontainersBuilder.Build())
 {
-  await testcontainer.StartAsync();
+  await testcontainers.StartAsync();
 
-  using (var connection = new NpgsqlConnection(testcontainer.ConnectionString))
+  using (var connection = new NpgsqlConnection(testcontainers.ConnectionString))
   {
     connection.Open();
 
@@ -153,6 +158,7 @@ Many thanks to [JetBrains](https://www.jetbrains.com/?from=dotnet-testcontainers
 
 This project is licensed under the MIT License - see the [LICENSE](LICENSE) file for details.
 
-[1]: https://github.com/HofmeisterAn/dotnet-testcontainers/blob/develop/src/DotNet.Testcontainers.Tests/Unit/Containers/Unix/TestcontainersContainerTest.cs
-[2]: https://github.com/HofmeisterAn/dotnet-testcontainers/blob/develop/src/DotNet.Testcontainers.Tests/Unit/Containers/Unix/Database
-[3]: https://github.com/HofmeisterAn/dotnet-testcontainers/blob/develop/src/DotNet.Testcontainers.Tests/Unit/Containers/Unix/MessageBroker
+[1]: https://github.com/HofmeisterAn/dotnet-testcontainers/blob/develop/tests/DotNet.Testcontainers.Tests/Unit/Containers/Unix/TestcontainersContainerTest.cs
+[2]: https://github.com/HofmeisterAn/dotnet-testcontainers/blob/develop/tests/DotNet.Testcontainers.Tests/Unit/Containers/Unix/Modules/Databases
+[3]: https://github.com/HofmeisterAn/dotnet-testcontainers/blob/develop/tests/DotNet.Testcontainers.Tests/Unit/Containers/Unix/Modules/MessageBrokers
+[moby-ryuk]: https://github.com/testcontainers/moby-ryuk
diff --git a/build.cake b/build.cake
index 0826bb846..fddd9ab61 100644
--- a/build.cake
+++ b/build.cake
@@ -74,20 +74,25 @@ Task("Build")
 Task("Tests")
   .Does(() =>
 {
-  DotNetTest(param.Solution, new DotNetTestSettings
+  foreach(var testProject in param.Projects.OnlyTests)
   {
-    Configuration = param.Configuration,
-    Verbosity = param.Verbosity,
-    NoRestore = true,
-    NoBuild = true,
-    Loggers = new[] { "trx" },
-    Filter = param.TestFilter,
-    ResultsDirectory = param.Paths.Directories.TestResults,
-    ArgumentCustomization = args => args
-      .Append("/p:CollectCoverage=true")
-      .Append("/p:CoverletOutputFormat=opencover")
-      .Append($"/p:CoverletOutput=\"{MakeAbsolute(param.Paths.Directories.TestCoverage)}/\"")
-  });
+    DotNetTest(testProject.Path.FullPath, new DotNetTestSettings
+    {
+      Configuration = param.Configuration,
+      Verbosity = param.Verbosity,
+      NoRestore = true,
+      NoBuild = true,
+      Loggers = new[] { "trx" },
+      Filter = param.TestFilter,
+      ResultsDirectory = param.Paths.Directories.TestResults,
+      ArgumentCustomization = args => args
+        .Append("/p:Platform=AnyCPU")
+        .Append("/p:CollectCoverage=true")
+        .Append("/p:CoverletOutputFormat=\"json%2copencover\"") // https://github.com/coverlet-coverage/coverlet/pull/220#issuecomment-431507570.
+        .Append($"/p:MergeWith=\"{MakeAbsolute(param.Paths.Directories.TestCoverage)}/coverage.net6.0.json\"")
+        .Append($"/p:CoverletOutput=\"{MakeAbsolute(param.Paths.Directories.TestCoverage)}/\"")
+    });
+  }
 });
 
 Task("Sonar-Begin")
diff --git a/tests/DotNet.Testcontainers.ResourceReaper.Tests/DefaultResourceReaperTest.cs b/tests/DotNet.Testcontainers.ResourceReaper.Tests/DefaultResourceReaperTest.cs
index 9f61408e5..5a3599740 100644
--- a/tests/DotNet.Testcontainers.ResourceReaper.Tests/DefaultResourceReaperTest.cs
+++ b/tests/DotNet.Testcontainers.ResourceReaper.Tests/DefaultResourceReaperTest.cs
@@ -7,6 +7,8 @@ namespace DotNet.Testcontainers.ResourceReaper.Tests
   using DotNet.Testcontainers.Tests.Unit;
   using Xunit;
 
+  // NOTICE: These tests stop the static shared default Resource Reaper (dispose). Unit tests are executed parallel.
+  // We cannot stop the default Resource Reaper all of a sudden. Run these tests in an isolated assembly.
   public sealed class DefaultResourceReaperTest : IAsyncLifetime
   {
     private static readonly string DefaultRyukContainerName = $"testcontainers-ryuk-{ResourceReaper.DefaultSessionId:D}";