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

samples/swarm/swarm_ui_lib/observable/observable.dart

Index: samples/swarm/swarm_ui_lib/observable/observable.dart
diff --git a/samples/swarm/swarm_ui_lib/observable/observable.dart b/samples/swarm/swarm_ui_lib/observable/observable.dart
index c5a040142f16a0d4bd3a251004a2ec62d5b372f5..17d87cdde213db99d43fbaa336cd02c8360f0259 100644
--- a/samples/swarm/swarm_ui_lib/observable/observable.dart
+++ b/samples/swarm/swarm_ui_lib/observable/observable.dart
@@ -215,7 +215,7 @@ class ObservableList<T>
   }
 
   int lastIndexOf(T element, [int start = null]) {
-    if (start === null) start = length - 1;
+    if (start == null) start = length - 1;
     return _internal.lastIndexOf(element, start);
   }
 
@@ -288,7 +288,7 @@ class ObservableValue<T> extends AbstractObservable {
     // TODO(terry): An object identity test === is needed.  Each DataSource has
     //              its own operator == which does a value compare.  Which
     //              equality check should be done?

[Lasse Reichstein Nielsen, 2012/11/12 13:10:41]

Remove comment. Using identical seems the right thing to do here.

[floitsch, 2012/11/12 22:18:43]

Done.

-    if (newValue !== _value) {
+    if (!identical(newValue, _value)) {
       final oldValue = _value;
       _value = newValue;
       recordPropertyUpdate("value", newValue, oldValue);