'A successful <Response> will contain one or more assertions containing
authentication statements.
:return:'

def create_authn_query_response(self, subject, session_index=None, requested_context=None, in_response_to=None, issuer=None, sign_response=False, status=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=[], **args)
