def verify_client(self, environ, areq, authn_method, client_id=""):
        """

        :param environ: WSGI environ
        :param areq: The request
        :param authn_method: client authentication method
        :return:
        """

        if not client_id:
            client_id = get_client_id(self.cdb, areq,
                                      environ["HTTP_AUTHORIZATION"])

        try:
            method = self.client_authn_methods[authn_method]
        except __HOLE__:
            raise UnSupported()
        return method(self).verify(environ, client_id=client_id)
dataset/ETHPy150Open rohe/pyoidc/src/oic/extension/provider.py/Provider.verify_client