 all contacts.
      TableCellBuilder th =
          tr.startTH().className(footerStyle).align(
              HasHorizontalAlignment.ALIGN_CENTER.getTextAlignString());
      th.text(ageStr);
      th.endTH();

      // Cells after age column.
      tr.startTH().colSpan(2).className(footerStyle).endTH();
      tr.endTR();

      return true;
    }
  }

  /**
   * Renders the data rows that display each contact in the table.
   */
  private class CustomTableBuilder extends AbstractCellTableBuilder&lt;Contact