public void resume() {
        execute(() ->  {
            if (state == State.STOPPED) {
                if (player == null) {
                    setState(State.NO_SONG, false);
                } else {
                    this.player.start();
                    this.timeLastStartTimestamp = System.currentTimeMillis();
                    setState(State.PLAYING, false);
                }
            }
        });
    }
Represents and manages one audio file or tone
main/src/main/java/cgeo/geocaching/utils/AudioManager.java