@Test
void shouldMuteVolumeWhenMuteButtonPressed() {

    mockVolumeSlider.setValue(0.5);
    StackPane result = (StackPane) musicControl.createMuteSwitchButton(mockVolumeSlider);
    Button mute = (Button) result.getChildren().get(0);
    mute.fire();
    assertEquals(0, mockVolumeSlider.getValue());
}