Support Expectation.identical.

lib/unittest/expectation.dart

Index: lib/unittest/expectation.dart
diff --git a/lib/unittest/expectation.dart b/lib/unittest/expectation.dart
index a0add00c0bf449aa476cb7541291c70a7d4c8b88..624605bd0f6c8ba1f84cef66fd668b0d6a7f28e9 100644
--- a/lib/unittest/expectation.dart
+++ b/lib/unittest/expectation.dart
@@ -38,6 +38,13 @@ class Expectation {
     Expect.approxEquals(expected, _value, tolerance: tolerance, reason: reason);
   }
 
+  /**
+   * Asserts that two objects are same (using [:===:]).
+   */
+  void same(expected) {
+    Expect.identical(_value, expected);
+  }
+
   /** Asserts that the value is [null]. */
   void isNull() {
     Expect.equals(null, _value);