@Test
public void shouldImplementThreadListener() {
    assertThat(config, is(instanceOf(ThreadListener.class)));
}
 

@Override
public void threadStarted() {
    if (wrapped instanceof ThreadListener) {
        ((ThreadListener) wrapped).threadStarted();
    }
}
 

@Override
public void threadFinished() {
    if (wrapped instanceof ThreadListener) {
        ((ThreadListener) wrapped).threadFinished();
    }
}