code: def create_authn_query_response(self, subject, session_index=None,
                                      requested_context=None, in_response_to=None,
                                      issuer=None, sign_response=False,
                                      status=None, sign_alg=None, digest_alg=None,
                                      **kwargs):
          
  
          margs = self.message_args()
          asserts = []
          for statement in self.session_db.get_authn_statements(
                  subject.name_id, session_index, requested_context):
              asserts.append(saml.Assertion(authn_statement=statement,
                                            subject=subject, **margs))
  
          if asserts:
              args = {"assertion": asserts}
          else:
              args = {}
  
          return self._response(in_response_to, "", status, issuer,
                                sign_response, to_sign=[], sign_alg=sign_alg,
                                digest_alg=digest_alg, **args)
docs: A successful <Response> will contain one or more assertions containing
          authentication statements.
  
          :return: