anchor.diff:        }
       }
   
  -    dom.HtmlElement cellElement = new dom.DivElement()..classes.add(cellCss);
  +    dom.HtmlElement cellElement = new dom.DivElement()
  +                                    ..classes.addAll(cellCss.split(" ").where((s) => s.length > 0));
   
       if (m.isDraggable) {
         cellElement.attributes['draggable'] = 'true';
  
positive.code: 
      dom.HtmlElement rowElement = new dom.DivElement()
        ..classes.add('ui-widget-content')
        ..classes.add(rowCss)
        ..style.top = '${_getRowTop(row)}px';
      //stringArray.add(rowElement);
  
      String colspan;
  
negative.code:           ..attributes["id"] = '${m.id}'
            ..attributes["title"] = m.toolTip != null ? m.toolTip : ""
            ..attributes['ismovable'] = '${m.isMovable}'
            ..column = m;
          if (m.headerCssClass != null) 
            header.classes.add(m.headerCssClass);
          _headers.append(header);
  
          if (_gridOptions.enableColumnReorder || m.sortable) {
  