anchor.diff:  /**
    * A library for writing dart unit tests.
    *
  - * To import this library, specify the relative path to
  - * pkg/unittest/unittest.dart.
  + * To import this library, use the pub package manager.
  + * Create a pubspec.yaml file in your project and add
  + * a dependency on unittest with the following lines:
  + *     dependencies:
  + *       unittest:
  + *         sdk: unittest
  + *         
  + * Then run 'pub install' from your project directory or using
  + * the DartEditor.
  + *         
  + * Please see [Pub Getting Started](http://pub.dartlang.org/doc)
  + * for more details about the pub package manager.
    *
    * ##Concepts##
    *
  
positive.code:  *
   * Multiple tests:
   *
   *     #import('path-to-dart/pkg/unittest/unitest.dart');
   *     main() {
   *       test('this is a test', () {
   *         int x = 2 + 3;
  
negative.code:  * that callback is run. A count argument can be provided to specify the number
   * of times the callback should be called (the default is 1).
   *
   *     import 'package:unittest/unittest.dart';
   *     import 'dart:isolate';
   *     main() {
   *       test('callback is executed once', () {
   *         // wrap the callback of an asynchronous call with [expectAsync0] if
   *         // the callback takes 0 arguments...
   *         var timer = new Timer(0, (_) => expectAsync0(() {
   *           int x = 2 + 3;
   *           expect(x, equals(5));
   *         }));
   *       });
   *
   *       test('callback is executed twice', () {
   *         var callback = (_) => expectAsync0(() {
   *           int x = 2 + 3;
   *           expect(x, equals(5));
   *         }, count: 2); // <-- we can indicate multiplicity to [expectAsync0]
   *         new Timer(0, callback);
   *         new Timer(0, callback);
   *       });
   *     }
   *
  