code: def _validate_empty(self, empty, field, value):
          
          if isinstance(value, Iterable) and len(value) == 0:
              self._drop_remaining_rules(
                  'allowed', 'forbidden', 'items', 'minlength', 'maxlength',
                  'regex', 'validator')
              if not empty:
                  self._error(field, errors.EMPTY_NOT_ALLOWED)
docs: {'type': 'boolean'}