@Test
public void testIsSpeaking() throws InterruptedException {

    NSSpeechSynthesizer ss = NSSpeechSynthesizer.synthesizerWithVoice(null);
    SynthesizerDelegate sd = new SynthesizerDelegate(ss);
    assertTrue(!ss.isSpeaking());
    ss.startSpeakingString("Hello world");
    assertTrue(ss.isSpeaking());
    sd.waitForSpeechDone(TIME_TO_WAIT, true);
}