<thead>
<tr>
  {% for key,cell in controller.iter_title %}
  <th id="column_{{ key }}" {{ cell.html_title_attr }} {% if cell.column.width %}width="{{ cell.column.width }}"{% endif %}>{% if cell.is_sortable %}{% include "table_column_sort.html" %}{% endif %}{{ cell.column.html_title }}</th>
  {% endfor %}
</tr>
</thead>
