render.js

render() {
  return (
    <table ref={(el) => (this.el = el)}>
      <thead>
        <tr>
          <th>#</th>
          <th>Title</th>
          <th>Completed</th>
          <th></th>
        </tr>
      </thead>
      <tbody>{this.props.children}</tbody>
    </table>
  );
}