code: def extend(self, name_id, issuer, vo_members):
          
          result = []
          for member in vo_members:
              for ass in self.metadata.attribute_consuming_service(member):
                  for attr_serv in ass.attribute_service:
                      logger.info(
                          "Send attribute request to %s", attr_serv.location)
                      if attr_serv.binding != BINDING_SOAP:
                          continue
                      # attribute query assumes SOAP binding
                      session_info = self.saml2client.attribute_query(
                          name_id, attr_serv.location, issuer_id=issuer,
  )
                      if session_info:
                          result.append(session_info)
          return result
docs: :param name_id: The identifier by which the subject is know
              among all the participents of the VO
          :param issuer: Who am I the poses the query
          :param vo_members: The entity IDs of the IdP who I'm going to ask
              for extra attributes
          :return: A dictionary with all the collected information about the
              subject