public void onVolumeDownButtonPressed(VolumeDownButtonPressedEvent event) {
volumeDownButtonEventSource.fire(new VolumeDownButtonEvent());
}
});
event.getVolumneUpButtonPressedHandler().addVolumneUpButtonPressedHandler(new VolumeUpButtonPressedHandler() {
@Override
public void onVolumeUpButtonPressed(VolumeUpButtonPressedEvent event) {
volumeUpButtonEventSource.fire(new VolumeUpButtonEvent());
}
});