code: function (element, options) {
      this.element  = element;
      this.options  = options;
      this.$overlay = $(options.overlayTemplate);
  
      if (options.source === '') {
        throw new Error('Source url was not defined. Please specify a url in your BoxRefresh source option.');
      }
  
      this._setUpListeners();
      this.load();
    }
docs: BoxRefresh Class Definition =========================