anchor.diff:   * 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('path-to-dart/pkg/unittest/unitest.dart');
  - *     #import('dart:html');
  + *     import 'package:unittest/unittest.dart';
  + *     import 'dart:isolate';
    *     main() {
  - *       test('calllback is executed once', () {
  + *       test('callback is executed once', () {
    *         // wrap the callback of an asynchronous call with [expectAsync0] if
    *         // the callback takes 0 arguments...
  - *         window.setTimeout(expectAsync0(() {
  + *         var timer = new Timer(0, (_) => expectAsync0(() {
    *           int x = 2 + 3;
    *           expect(x, equals(5));
  - *         }), 0);
  + *         }));
    *       });
    *
  - *       test('calllback is executed twice', () {
  - *         var callback = expectAsync0(() {
  + *       test('callback is executed twice', () {
  + *         var callback = (_) => expectAsync0(() {
    *           int x = 2 + 3;
    *           expect(x, equals(5));
    *         }, count: 2); // <-- we can indicate multiplicity to [expectAsync0]
  - *         window.setTimeout(callback, 0);
  - *         window.setTimeout(callback, 0);
  + *         new Timer(0, callback);
  + *         new Timer(0, callback);
    *       });
    *     }
    *
  
positive.code: /**
   * A library for writing dart unit tests.
   *
   * To import this library, specify the relative path to
   * pkg/unittest/unittest.dart.
   *
   * ##Concepts##
   *
  
negative.code:  *
   * Multiple tests:
   *
   *     import 'package:unittest/unittest.dart';
   *     main() {
   *       test('this is a test', () {
   *         int x = 2 + 3;
  