s="display:{{showColumnHeader ? 'table-header-group' : 'none'}}">
          <tr>
            <th template repeat="{{column in columns}}" class="ui-state-default">
              <span>
                <h-safe-html content="{{column.header}}"></h-safe-html>
              </span>
              
              <template if="{{column.resizable}}">
                <span class="column-resizer" on-mousedown="{{onColumnResizeStarted}}">&nbsp;</span>
              </template>
            </th>
          </tr>
        