docs: function(holder, options) {
  			var self = this;
  			self.options = options || {};
  			self.box = holder;
  			if (!self.box) {
  				throw "实例 IndexedList 时需要指定 element";
  			}
  			self.createDom();
  			self.findElements();
  			self.caleLayout();
  			self.bindEvent();
  		}