est passes if the table below has two blue rows on top and two purple rows on the bottom.</p>
        <table>
            <tbody id="tb1">
                <tr>
                    <td></td>
                    <td></td>
                    <td></td>
                    <td></td>
                </tr>
                <tr>
                    <td></td>
                    <td></td>
                    <td></td>
                    <td></td>
                </tr>
            </tbody>
          