docs: function(){
        var uri = 'https://img.youtube.com/vi/' + this.url.videoId + '/maxresdefault.jpg';
  
        try {
          var image = new Image();
          image.onload = function(){
            // Onload may still be called if YouTube returns the 120x90 error thumbnail
            if('naturalHeight' in image){
              if (image.naturalHeight <= 90 || image.naturalWidth <= 120) {
                return;
              }
            } else if(image.height <= 90 || image.width <= 120) {
              return;
            }
  
            this.poster_ = uri;
            this.trigger('posterchange');
          }.bind(this);
          image.onerror = function(){};
          image.src = uri;
        }
        catch(e){}
      }