@Test
public void should_reactOnDifferentEvents() {

    Message result = b.process(execFinishEvent);
    assertThat(result, is(equalTo(Message.NULL)));
    assertThat("Incorrect sequence of events", executionFinished && !commit && !executionStart);
    result = b.process(commitEvent);
    assertThat(result, is(equalTo(Message.NULL)));
    assertThat("Incorrect sequence of events", executionFinished && commit && !executionStart);
    result = b.process(execStartEvent);
    assertThat(result, is(equalTo(Message.NULL)));
    assertThat("Incorrect sequence of events", executionFinished && commit && executionStart);
}