code: public void addValidator(Validator validator)
      {
          if (validator == null)
          {
              throw new NullPointerException("validator");
          }
          
          if (_validatorList == null)
          {
              //normally add user 0-3 validators: 
              _validatorList = new _DeltaList<Validator>(new ArrayList<Validator>(3));
          }
  
          _validatorList.add(validator);
          
          // The argument validator must be inspected for the presence of the ResourceDependency annotation.
          //_handleAnnotations(FacesContext.getCurrentInstance(), validator);
      }
docs: See getValidator.