docs: function createContentGroupSumRow(groupRow, createFlag) {
      if (this.options.groupSumRow) {
          var oThis = this,
              idStr,
              groupValue = groupRow.value;
          if (createFlag == 'fixed') {
              idStr = 'fixed_';
          } else {
              idStr = '';
          }
          var htmlStr = '<tr role="groupsumrow" groupValue="' + groupValue + '" class="u-grid-content-group-sum-row" id="' + this.options.id + '_content_' + idStr + 'group_sum_row_' + groupValue + '">';
          htmlStr += createContentGroupSumRowTd.call(this, groupRow, createFlag);
          htmlStr += '</tr>';
          return htmlStr;
      }
  }