def _get_token(self, token, http_conn_id):
        """
        
        """
        if token:
            return token
        elif http_conn_id:
            conn = self.get_connection(http_conn_id)
            extra = conn.extra_dejson
            return extra.get('webhook_token', '')
        else:
            raise AirflowException('Cannot get token: No valid Slack '
                                   'webhook token nor conn_id supplied')