def get_client_secret(self, client_key, request):
log.debug('<STR_LIT>', client_key)<EOL>if not request.client:<EOL><INDENT>request.client = self._clientgetter(client_key=client_key)<EOL><DEDENT>if request.client:<EOL><INDENT>return request.client.client_secret<EOL><DEDENT>return None<EOL>
Get client secret.

        The client object must has ``client_secret`` attribute.