docs: function () {
          var list = slice.call(this.indexes || []);
          var i = 0;
          list.push(this.mainIndex);
          list.push('cid');
          var l = list.length;
          this.models = [];
          this._indexes = {};
          for (; i < l; i++) {
              this._indexes[list[i]] = {};
          }
      }