@Override
  public Instant currentProcessingTime() {
    return processingTimeClock.now();
  }
@Test
  public void getProcessingTimeIsClockNow() {
    assertThat(internals.currentProcessingTime(), equalTo(clock.now()));
    Instant oldProcessingTime = internals.currentProcessingTime();

    clock.advance(Duration.standardHours(12));

    assertThat(internals.currentProcessingTime(), equalTo(clock.now()));
    assertThat(
        internals.currentProcessingTime(),
        equalTo(oldProcessingTime.plus(Duration.standardHours(12))));
  }