code: function() {
          var selected = this.$rightListBody.find(':checkbox'),
              keyMap = this.options.keyMap;
          return $.map(selected, function(value, index) {
              var result = {};
              result[keyMap.id] = $(value).attr('data-id');
              result[keyMap.title] = $(value).next()[0].lastChild.nodeValue;
              return result;
          });
      }
docs: 获取已选数据项
  @return {Array}