ation.</li>
<li><strong>sort</strong> [Function] - A callback to get the value for sorting, if different then <code>value</code>; also sets <code>sortable</code> to true.</li>
<li><strong>sort_ascending</strong> [Boolean] - Sort the rows based on ascending value instead of descending.</li>
<li><strong>vis</strong> [String] Optional type of visualization for the <em>value</em> of the cells in this column.  Options include:<ul>
<li><em>bar</em> - The value is represented as a horizontal bar across the cell un