colspan in top row makes cells below not resizable

[HaKr]

When the first visible row of a table has cells with colspan>1, cells below it are not resizable.

      <thead>
        <tr>
          <th data-resizable-column-id="#">#</th>
          <th data-resizable-column-id="first_name" colspan=2>First & last Name</th>
          <th data-resizable-column-id="username" id="username-column">Username</th>
        </tr>
      </thead>
      <tbody>
        <tr>
          <td>1</td>
          <td>Mark</td>
          <td>Otto</td>
          <td>@mdo</td>
        </tr>

This slightly adapted version of the demo, gives only two resize handles.

	<div class="rc-handle-container" style="width: 1139px;">
		<div class="rc-handle" style="left: 71px; height: 149px;"></div>
		<div class="rc-handle" style="left: 943.067px; height: 149px;"></div>
	</div>

Is there a way to have the third handle be added?