docs: function createColgroup(createFlag) {
      var oThis = this,
          htmlStr = '<colgroup>',
          gridCompColumnArr;
      if (createFlag == 'fixed') {
          gridCompColumnArr = this.gridCompColumnFixedArr;
      } else {
          gridCompColumnArr = this.gridCompColumnArr;
      }
      $.each(gridCompColumnArr, function () {
          if (this.options.visible) {
              htmlStr += '<col';
              if (!this.options.autoExpand) {
                  htmlStr += ' style="width:' + oThis.formatWidth(this.options.width) + '"';
              }
              htmlStr += '>';
          }
      });
      htmlStr += '</colgroup>';
      return htmlStr;
  }