@Test
    public void testChangemusic() {
        Sandbox.changemusic("1");
        MediaPlayer elozo = Sandbox.mediaPlayer;
        Sandbox.changemusic("3");
        Sandbox.playmusic();
        assertNotSame(Sandbox.mediaPlayer, elozo);
    }

    @Test
    public void testPlaymusic() {

        Sandbox.changemusic("3");
        Sandbox.playmusic();

        assertEquals(Sandbox.mediaPlayer.isMute(), false);

    }

    @Test
    public void testStopmusic() {

        Sandbox.changemusic("3");
        Sandbox.playmusic();
        Sandbox.stopmusic();

        assertFalse(Sandbox.mediaPlayer.isAutoPlay());
    }