问LibGDX -在Gdx.audio.newMusic()中分配任务后如何从Gdx.audio.newMusic设备中删除文件；

EN

public class TEST_Android
{
    public static Music M = null;

    // *** Test: Delete-file WITHOUT assignment ***
    //
    public void TEST_A()
    {
        Gdx.files.local("PurpleRain.ogg").delete();                // work 100%
        //
        // --- i've checked the file on Android mobile and is NOT present
        // --- has been deleted correctly
    }



    // *** Test: Delete-file AFTER assignment ***
    //
    public void TEST_B()
    {
        M = Gdx.audio.newMusic(Gdx.files.local("PurpleRain.ogg")); // work 100%
        M.play();                                                  // work 100%
        M.stop();                                                  // work 100%

        M.delete();                                                // doesn't work!
        //
        // --- i've checked the file on Android mobile and is ever present!
        // --- not deleted...
    }
}