docs: function(ordinal, object) {
          var node, ord, idx, lastIndex = this.cellCount() - 1;
          idx = ordinal > lastIndex ? lastIndex : ordinal;
          while(true) {
              node = this._cellNodes[idx];
              ord = this._getCellOrdinal(node);
              if (ord === ordinal) return this.getByIndex(idx, object);
              else
              if (ord > ordinal) idx--;
              else return null;
          }
      }