class Speakerbox implements TextToSpeech.OnInitListener {

    public void play(CharSequence text) {
        play(text.toString(), null, null, null);
    }

}

class SpeakerboxTest {

    private Activity activity;
    private Speakerbox speakerbox;
    private com.mapzen.speakerbox.ShadowTextToSpeech shadowTextToSpeech;

    @Test
    public void shouldPlayCharacterSequence() throws Exception {

        CharSequence expected = "Hello";
        speakerbox.play(expected);
        assertThat(shadowTextToSpeech.getLastSpokenText()).isEqualTo(expected.toString());
    }

}