@Test
public void shouldReturnCreatedJobId() {

    // given:
    when(jobRunnable.getJobDefinition()).thenReturn(someJobDefinition("BAR"));
    // when:
    Optional<String> jobId = jobService.startAsyncJob("BAR");
    // then:
    assertThat(jobId.isPresent(), is(true));
    assertThat(jobId.get(), not(isEmptyOrNullString()));
}