anchor.diff:              controller.add(null);
               async.elapse(const Duration(minutes: 1));
               return ret;
  -          });
  +          }));
           });
   
           test('should increase negative duration timers to zero duration', () {
  
positive.code:         });
  
          test('should add event before advancing time', () {
            return new FakeAsync().run((async) {
              var controller = new StreamController();
              var ret = controller.stream.first.then((_) {
                expect(async.getClock(initialTime).now(), initialTime);
  
negative.code:             expect(errors.first, new isInstanceOf<TimeoutException>());
              return controller.close();
            });
          });
        });
      });
    });
  }
  