code: public ValidationMessage[] validate( TagData data ) {
  	TagExtraInfo tei = getTagExtraInfo();
  	if( tei == null ) {
  	    return null;
  	}
  	return tei.validate( data );
      }
docs: Translation-time validation of the attributes.
  This is a convenience method on the associated TagExtraInfo class.
  
  @param data The translation-time TagData instance.
  @return A null object, or zero length array if no errors, an
  array of ValidationMessages otherwise.
  @since JSP 2.0