a === b -> identical(a, b)

samples/swarm/swarm_ui_lib/touch/Geometry.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // 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.
 
 /**
  * Represents a point in 2 dimensional space.
  */
 class Coordinate {
 
   /**
@@ skipping 19 matching lines @@
     return new Coordinate(a.x - b.x, a.y - b.y);
   }
 
   static num distance(Coordinate a, Coordinate b) {
     final dx = a.x - b.x;
     final dy = a.y - b.y;
     return Math.sqrt(dx * dx + dy * dy);
   }
 
   bool operator ==(Coordinate other) {
-    return other !== null && x == other.x && y == other.y;
+    return other != null && x == other.x && y == other.y;
   }
 
   static num squaredDistance(Coordinate a, Coordinate b) {
     final dx = a.x - b.x;
     final dy = a.y - b.y;
     return dx * dx + dy * dy;
   }
 
   static Coordinate sum(Coordinate a, Coordinate b) {
     return new Coordinate(a.x + b.x, a.y + b.y);
@@ skipping 15 matching lines @@
   final num start;
   final num end;
 
   Interval(num this.start, num this.end) {}
 
   num get length {
     return end - start;
   }
 
   bool operator ==(Interval other) {
-    return other !== null && other.start == start && other.end == end;
+    return other != null && other.start == start && other.end == end;
   }
 
   Interval union(Interval other) {
     return new Interval(Math.min(start, other.start),
                         Math.max(end, other.end));
   }
 
   bool contains(num value) {
     return value >= start && value < end;
   }
 
   String toString() {
     return '(${start}, ${end})';
   }
 }