diff --git a/lib/src/async_environment.dart b/lib/src/async_environment.dart
index 3f03344ea..5c1b2d33b 100644
--- a/lib/src/async_environment.dart
+++ b/lib/src/async_environment.dart
@@ -314,7 +314,7 @@ class AsyncEnvironment {
       }
 
       if (type == "variable") name = "\$$name";
-      var span = _forwardedModuleNodes.andGet(oldModule)?.span;
+      var span = _forwardedModuleNodes?[oldModule]?.span;
       throw MultiSpanSassScriptException(
           'Two forwarded modules both define a $type named $name.',
           "new @forward",
@@ -617,7 +617,7 @@ class AsyncEnvironment {
     _lastVariableName = name;
     _lastVariableIndex = index;
     _variables[index][name] = value;
-    _variableNodes?.andGet(index)![name] = nodeWithSpan!;
+    _variableNodes?[index][name] = nodeWithSpan!;
   }
 
   /// Sets the variable named [name] to [value], associated with
@@ -636,7 +636,7 @@ class AsyncEnvironment {
     _variableIndices[name] = index;
     _variables[index][name] = value;
     if (nodeWithSpan != null) {
-      _variableNodes?.andGet(index)![name] = nodeWithSpan;
+      _variableNodes?[index][name] = nodeWithSpan;
     }
   }
 
@@ -818,7 +818,7 @@ class AsyncEnvironment {
     var configuration = <String, ConfiguredValue>{};
     for (var i = 0; i < _variables.length; i++) {
       var values = _variables[i];
-      var nodes = _variableNodes.andGet(i) ?? <String, AstNode>{};
+      var nodes = _variableNodes?[i] ?? <String, AstNode>{};
       for (var entry in values.entries) {
         // Implicit configurations are never invalid, making [configurationSpan]
         // unnecessary, so we pass null here to avoid having to compute it.
diff --git a/lib/src/environment.dart b/lib/src/environment.dart
index b120e0511..da4910951 100644
--- a/lib/src/environment.dart
+++ b/lib/src/environment.dart
@@ -5,7 +5,7 @@
 // DO NOT EDIT. This file was generated from async_environment.dart.
 // See tool/grind/synchronize.dart for details.
 //
-// Checksum: 1ef0f32701764f4b160ef045ca162b38653e0504
+// Checksum: bb0b47fc04e32f36a0f87dc73bdfe3f89dc51aa4
 //
 // ignore_for_file: unused_import
 
@@ -322,7 +322,7 @@ class Environment {
       }
 
       if (type == "variable") name = "\$$name";
-      var span = _forwardedModuleNodes.andGet(oldModule)?.span;
+      var span = _forwardedModuleNodes?[oldModule]?.span;
       throw MultiSpanSassScriptException(
           'Two forwarded modules both define a $type named $name.',
           "new @forward",
@@ -625,7 +625,7 @@ class Environment {
     _lastVariableName = name;
     _lastVariableIndex = index;
     _variables[index][name] = value;
-    _variableNodes?.andGet(index)![name] = nodeWithSpan!;
+    _variableNodes?[index][name] = nodeWithSpan!;
   }
 
   /// Sets the variable named [name] to [value], associated with
@@ -644,7 +644,7 @@ class Environment {
     _variableIndices[name] = index;
     _variables[index][name] = value;
     if (nodeWithSpan != null) {
-      _variableNodes?.andGet(index)![name] = nodeWithSpan;
+      _variableNodes?[index][name] = nodeWithSpan;
     }
   }
 
@@ -824,7 +824,7 @@ class Environment {
     var configuration = <String, ConfiguredValue>{};
     for (var i = 0; i < _variables.length; i++) {
       var values = _variables[i];
-      var nodes = _variableNodes.andGet(i) ?? <String, AstNode>{};
+      var nodes = _variableNodes?[i] ?? <String, AstNode>{};
       for (var entry in values.entries) {
         // Implicit configurations are never invalid, making [configurationSpan]
         // unnecessary, so we pass null here to avoid having to compute it.
diff --git a/lib/src/util/merged_map_view.dart b/lib/src/util/merged_map_view.dart
index b84f6ad51..df749871f 100644
--- a/lib/src/util/merged_map_view.dart
+++ b/lib/src/util/merged_map_view.dart
@@ -5,8 +5,6 @@
 import 'dart:collection';
 
 import '../utils.dart';
-import '../util/nullable.dart';
-import 'nullable.dart';
 
 /// An unmodifiable view of multiple maps merged together as though they were a
 /// single map.
@@ -46,7 +44,7 @@ class MergedMapView<K, V> extends MapBase<K, V> {
     }
   }
 
-  V? operator [](Object? key) => _mapsByKey[key as K].andGet(key);
+  V? operator [](Object? key) => _mapsByKey[key as K]?[key];
 
   operator []=(K key, V value) {
     var child = _mapsByKey[key];
diff --git a/lib/src/util/nullable.dart b/lib/src/util/nullable.dart
index 7d1511dc8..f5bf6258c 100644
--- a/lib/src/util/nullable.dart
+++ b/lib/src/util/nullable.dart
@@ -13,26 +13,6 @@ extension NullableExtension<T> on T? {
   }
 }
 
-extension NullableListExtension<T> on List<T>? {
-  /// If [this] is `null`, returns `null`. Otherwise, returns `this[index]`.
-  ///
-  /// This is the equivalent of `list?.[key]`, if such a thing existed.
-  T? andGet(int index) {
-    var self = this;
-    return self == null ? null : self[index];
-  }
-}
-
-extension NullableMapExtension<K, V> on Map<K, V>? {
-  /// If [this] is `null`, returns `null`. Otherwise, returns `this[key]`.
-  ///
-  /// This is the equivalent of `map?.[key]`, if such a thing existed.
-  V? andGet(Object? key) {
-    var self = this;
-    return self == null ? null : self[key];
-  }
-}
-
 extension SetExtension<T> on Set<T?> {
   /// Destructively removes the `null` element from this set, if it exists, and
   /// returns a view of it casted to a non-nullable type.
diff --git a/lib/src/visitor/async_evaluate.dart b/lib/src/visitor/async_evaluate.dart
index 0cac6b70b..83b910270 100644
--- a/lib/src/visitor/async_evaluate.dart
+++ b/lib/src/visitor/async_evaluate.dart
@@ -2219,7 +2219,7 @@ class _EvaluateVisitor
             _environment.setLocalVariable(
                 declaredArguments[i].name,
                 evaluated.positional[i].withoutSlash(),
-                evaluated.positionalNodes.andGet(i));
+                evaluated.positionalNodes?[i]);
           }
 
           for (var i = evaluated.positional.length;
@@ -2231,7 +2231,7 @@ class _EvaluateVisitor
             _environment.setLocalVariable(
                 argument.name,
                 value.withoutSlash(),
-                evaluated.namedNodes.andGet(argument.name) ??
+                evaluated.namedNodes?[argument.name] ??
                     argument.defaultValue.andThen(_expressionNode));
           }
 
diff --git a/lib/src/visitor/evaluate.dart b/lib/src/visitor/evaluate.dart
index 3b8bce68a..dc2b70566 100644
--- a/lib/src/visitor/evaluate.dart
+++ b/lib/src/visitor/evaluate.dart
@@ -5,7 +5,7 @@
 // DO NOT EDIT. This file was generated from async_evaluate.dart.
 // See tool/grind/synchronize.dart for details.
 //
-// Checksum: 01a7ae41ae622e64443597ea82b27b7aeb73d260
+// Checksum: 6b82405fdc448ac69ca703bc6bffbb8d50f3fced
 //
 // ignore_for_file: unused_import
 
@@ -2206,7 +2206,7 @@ class _EvaluateVisitor
             _environment.setLocalVariable(
                 declaredArguments[i].name,
                 evaluated.positional[i].withoutSlash(),
-                evaluated.positionalNodes.andGet(i));
+                evaluated.positionalNodes?[i]);
           }
 
           for (var i = evaluated.positional.length;
@@ -2218,7 +2218,7 @@ class _EvaluateVisitor
             _environment.setLocalVariable(
                 argument.name,
                 value.withoutSlash(),
-                evaluated.namedNodes.andGet(argument.name) ??
+                evaluated.namedNodes?[argument.name] ??
                     argument.defaultValue.andThen(_expressionNode));
           }