tent="Table column groups in themselves are not rendered." />
        <style type="text/css">
            #table
            {
                display: table;
            }
            #colgroup
            {
                background: red;
                display: table-column-group;
                height: 5em;
                width: 5em;
            }
        </style>
    </head>
    <body>
        <p>Test passes if there is no red visible on the page.</p>
        <div id="table">
            <div id="c