### Question:
StoppedKamonTimer implements StoppedTimer { @Override public Duration getDuration() { return Duration.ofNanos(this.endTimestamp - this.startTimestamp); } private  StoppedKamonTimer(final String name, final Map<String, String> tags, final long startTimestamp,
            final Map<String, StartedTimer> segments, List<OnStopHandler> onStopHandlers); @Override Duration getDuration(); @Override Map<String, String> getTags(); @Nullable @Override String getTag(final String key); @Override String getName(); @Override String toString();  }### Answer:
@Test public void getDuration() { assertThat(sut.getDuration().toNanos()).isGreaterThan(0); }