>vertical_lines</th>
      <td><p>If you would like to add dashed vertical lines to help
visual interpretation of numbers. Default is to not show (<code>FALSE</code>),
to turn on write <code>TRUE</code>.</p></td>
    </tr>
    <tr>
      <th>horizontal_lines</th>
      <td><p>If <code>TRUE</code> (default), horizontal dashed lines will
appear behind the bars of the pyramid</p></td>
    </tr>
    <tr>
      <th>pyramid</th>
      <td><p>if <code>TRUE</code>, then binary <code>split_by</code> variables will r