code: public void setAttribute(String name, String value, String facet) throws JspException {
          if(facet == null || facet.equals(ATTRIBUTE_HEADER_NAME)) {
              super.addStateAttribute(_cellState, name, value);
          }
          else {
              String s = Bundle.getString("Tags_AttributeFacetNotSupported", new Object[]{facet});
              throw new JspException(s);
          }
      }
docs: <p>
  Implementation of the {@link org.apache.beehive.netui.tags.IAttributeConsumer} interface.  This
  allows users of the anchorCell tag to extend the attribute set that is rendered by the HTML
  anchor.  This method accepts the following facets:
  <table>
  <tr><td>Facet Name</td><td>Operation</td></tr>
  <tr><td><code>header</code></td><td>Adds an attribute with the provided <code>name</code> and <code>value</code> to the
  attributes rendered on the &lt;th&gt; tag.</td></tr>
  </table>
  The HeaderCell tag defaults to the setting attributes on the header when the facet name is unset.
  </p>
  @param name the name of the attribute
  @param value the value of the attribute
  @param facet the facet for the attribute
  @throws JspException thrown when the facet is not recognized