function Player() { } Player.prototype.play = function(song) {

this.currentlyPlayingSong = song;
this.isPlaying = true;

};

Player.prototype.pause = function() {

this.isPlaying = false;

};

Player.prototype.resume = function() {

if (this.isPlaying) {
  throw new Error("song is already playing");
}

this.isPlaying = true;

};

Player.prototype.makeFavorite = function() {

this.currentlyPlayingSong.persistFavoriteStatus(true);

};