code: @Override
      public Iterator<String> getExcludedValidatorIds()
      {
          if (_excludedValidatorIdsStack != null && !_excludedValidatorIdsStack.isEmpty())
          {
              return _excludedValidatorIdsStack.iterator();
          }
          return null;
      }
docs: Gets all validationIds on the stack.
  @return
  @since 2.0