docs: def raw(self):
          """Make request to url and return the raw response object.
          """
          try:
              return urlopen(str(self.url))
          except HTTPError as error:
              try:
                  # parse error body as json and use message property as error message
                  parsed = self._parsejson(error)
                  exc = RequestError(parsed['message'])
                  exc.__cause__ = None
                  raise exc
              except ValueError:
                  # when error body is not valid json, error might be caused by server
                  exc = StatbankError()
                  exc.__cause__ = None
                  raise exc