public static VolumeAction fadeIn(final Music music, final float duration, final Interpolation interpolation) {
        return setVolume(music, 0f, 1f, duration, interpolation);
    }
public static VolumeAction fadeIn ( final Music music , final float duration , final Interpolation interpolation ) { return setVolume ( music , 0f , 1f , duration , interpolation ) ; }
@param music its volume will go from 0 to 1.
@param duration length of the transition.
@param interpolation handles how the volume is changed in time.
@return {@link VolumeAction} which should be added to a stage.