对的. `params`里传cache就是用来判断的. 只有在new Player时传入{cache: true}才会写入文件到本地.
 https://github.com/fraserxu/player/commit/14c9c8ff72646bb481f8889f17c60ad415b12849#diff-168726dbe96b3ce427e7fedce31bb0bcR121