code: function PreviewThumbnails(player) {
  	    _classCallCheck(this, PreviewThumbnails);
  
  	    this.player = player;
  	    this.thumbnails = [];
  	    this.loaded = false;
  	    this.lastMouseMoveTime = Date.now();
  	    this.mouseDown = false;
  	    this.loadedImages = [];
  	    this.elements = {
  	      thumb: {},
  	      scrubbing: {}
  	    };
  	    this.load();
  	  }
docs: PreviewThumbnails constructor.
  @param {Plyr} player
  @return {PreviewThumbnails}