Migrate utils/comparators

Signed-off-by: Gavin Zhao <[email protected]>

angular_components/lib/utils/comparators/comparators.dart

@@ -2,7 +2,7 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-// @dart=2.9
+// ignore_for_file: hash_and_equals
 
 /// Use this as a mixin to be able to use arithmetic comparison operators
 /// in your class.
@@ -17,7 +17,9 @@ abstract class Comparators<T> implements Comparable<T> {
 
   @override
   bool operator ==(other) =>
-      other is T && runtimeType == other.runtimeType && compareTo(other) == 0;
+      other is T &&
+      runtimeType == other.runtimeType &&
+      compareTo(other as T) == 0;
 }
 
 /// This can be extended in classes that are using const constructors.
@@ -33,5 +35,7 @@ abstract class ConstComparators<T> implements Comparable<T> {
 
   @override
   bool operator ==(other) =>
-      other is T && runtimeType == other.runtimeType && compareTo(other) == 0;
+      other is T &&
+      runtimeType == other.runtimeType &&
+      compareTo(other as T) == 0;
 }