anchor.diff:        shouldPass(d, isEmpty);
         shouldFail(e, isEmpty, "Expected: empty but: was <[1]>.");
       });
  -    
  +
       test('contains', () {
         var d = new SimpleIterable(3);
         shouldPass(d, contains(2));
         shouldFail(d, contains(5), "Expected: contains <5> but: was <[3]>.");
       });
     });
  -  
  +
     group('Iterable Matchers', () {
   
       test('isEmpty', () {
  
positive.code:         "but:  exception <Exception> does not match "
              "UnsupportedError.");
      });
      
      test('throwsStateError', () {
        shouldPass(() { throw new StateError(''); },
            throwsStateError);
  
negative.code:   featureValueOf(actual) => actual.price;
  }
  
  class SimpleIterable extends IterableBase {
    int count;
    SimpleIterable(this.count);
  
    bool contains(int val) => count < val ? false : true;
  
    bool any(bool f(element)) {
      for(var i = 0; i <= count; i++) {
        if(f(i)) return true;
      }
      return false;
    }
  
    String toString() => "<[$count]>";
  
    Iterator get iterator {
  