@Test
  public void start_whenRunning_shouldNotScheduleAndRunShouldScheduleWithNewInterval() {
    subject.startRepeating(100l);
    reset(mockHandler);

    subject.startRepeating(200l);

    verifyZeroInteractions(mockHandler);

    subject.run();

    verify(mockHandler).postDelayed(eq(subject), eq(200l));
  }
  @Test
  public void startTracking_whenRunning_shouldScheduleSelf() {
    subject.startRepeating(100);
    reset(mockHandler);
    subject.run();

    verify(mockHandler).postDelayed(eq(subject), eq(100l));
  }
  @Test
  public void stopTracking_whenRunning_shouldPreventNextScheduling() {
    subject.startRepeating(100l);
    verify(mockHandler).post(eq(subject));

    subject.run();
    verify(mockHandler).postDelayed(eq(subject), eq(100l));

    reset(mockHandler);
    subject.stop();

    subject.run();
    verifyZeroInteractions(mockHandler);
  }