<p>Simple header</p>

<table>
  <thead>
    <tr>
      <th>cell1</th>
      <th>cell2</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>cell3</td>
      <td>cell4</td>
    </tr>
  </tbody>
</table>

<p>Full header</p>

<table>
  <thead>
    <tr>
      <th>cell1</th>
      <th>cell2</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>cell3</td>
      <td>cell4</td>
    </tr>
  </tbody>
</table>

<p>With alignment and superfluous alignment defs</p>

<table>
  <thead>
    <tr>
      <th>default</th>
  