 String cellStyles = cellStyle;
      if (isSelected) {
        cellStyles += selectedCellStyle;
      }
      if (isFriend) {
        cellStyles += childCell;
      }

      TableRowBuilder row = startRow();
      row.className(trClasses.toString());

      /*
       * Checkbox column.
       * 
       * This table will uses a checkbox column for selection. Alternatively,
       * you can call dataGrid.setSelectionEnabled(true) to enable mouse
       * selection.
       */
      TableCellBuilder td = row.s