docs: public static <T> T findAttributeParent(String fromTagName, JspTag from, String attribute, Class<? extends T> clazz) throws NeedAttributeParentException {
  		T parent = clazz.cast(SimpleTagSupport.findAncestorWithClass(from, clazz));
  		if(parent==null) throw new NeedAttributeParentException(fromTagName, attribute);
  		return parent;
  	}