src/main/java/org/intellimate/izou/sdk/frameworks/music/player/template/Player.java
public void rollBackToDefault() {
        playlist = new Playlist(new ArrayList<>());
        volume = Volume.createVolume(50).orElse(null);
        progress = new Progress(0,0);
        playbackState = PlaybackState.PLAY;
        if (playingThread != null)
            playingThread.cancel(true);
        isRunning = false;
        isPlaying = false;
    }
public void rollBackToDefault() {
        playlist = new Playlist(new ArrayList<>());
        volume = Volume.createVolume(50).orElse(null);
        progress = new Progress(0,0);
        playbackState = PlaybackState.PLAY;
        if (playingThread != null)
            playingThread.cancel(true);
        isRunning = false;
        isPlaying = false;
    }
sets every information into its default state (playlist, volume, etc...)