docs: def make_error(self,
                     message: str,
                     *,
                     error: Exception = None,
                     # ``error_class: Type[Exception]=None`` doesn't work on
                     # Python 3.5.2, but that is exact version ran by Read the
                     # Docs :( More info: http://stackoverflow.com/q/42942867
                     error_class: Any = None) -> Exception:
          """Return error instantiated from given message.
  
          :param message: Message to wrap.
          :param error: Validation error.
          :param error_class:
              Special class to wrap error message into. When omitted
              ``self.error_class`` will be used.
          """
          if error_class is None:
              error_class = self.error_class if self.error_class else Error
          return error_class(message)