### Question:
MetricService { public void log(final AvatarType avatarType) { Objects.requireNonNull(avatarType); final LocalDateTime now = LocalDateTime.now(clock); avatarUpdatedRepository.set(avatarType, now); }  void log(final AvatarType avatarType); List<Metric> collect(); void send(final List<Metric> metrics);  }### Answer:
@Test public void logTest() { doNothing().when(avatarUpdatedRepository).set(AvatarType.GRAVATAR, NOW); metricService.log(AvatarType.GRAVATAR); verify(avatarUpdatedRepository).set(AvatarType.GRAVATAR, NOW); }