@Override
 public void validateTag() throws JspException {
   if (type != null && !Output.validate(type)) {
     throw InvalidAttributeException.fromPossibleValues("output", "type", Output.getValues());
   }
   if (align != null && !Align.validate(align)) {
     throw InvalidAttributeException.fromPossibleValues("output", "align", Align.getValues());
   }
   if (transform != null && !Case.validate(transform)) {
     throw InvalidAttributeException.fromPossibleValues("output", "transform", Case.getValues());
   }
   if (look != null && !Look.validateText(look) && !isEL(look)) {
     throw InvalidAttributeException.fromPossibleValues("output", "look", Look.getTextValues());
   }
 }