docs: def _deserialize(self, value, attr, data, **kwargs):
          """Deserialize an ISO8601-formatted time to a :class:`datetime.time` object."""
          if not value:  # falsy values are invalid
              self.fail('invalid')
          try:
              return utils.from_iso_time(value)
          except (AttributeError, TypeError, ValueError):
              self.fail('invalid')