def notify_mpp_coordinator(self, event: str) -> None:
        """Send an event to the MPP coordinator.

        :param event: the type of event for coordinator to parse.
        """
        mpp_handler = self.state_handler.mpp_handler
        if mpp_handler.is_worker():
            coordinator = self.dcs.get_mpp_coordinator()
            if coordinator and coordinator.leader and coordinator.leader.conn_url:
                try:
                    data = {'type': event,
                            'group': mpp_handler.group,
                            'leader': self.state_handler.name,
                            'timeout': self.dcs.ttl,
                            'cooldown': self.patroni.config['retry_timeout']}
                    timeout = self.dcs.ttl if event == 'before_demote' else 2
                    endpoint = 'citus' if mpp_handler.type == 'Citus' else 'mpp'
                    self.patroni.request(coordinator.leader.member, 'post', endpoint, data, timeout=timeout, retries=0)
                except Exception as e:
                    logger.warning('Request to %s coordinator leader %s %s failed: %r', mpp_handler.type,
                                   coordinator.leader.name, coordinator.leader.member.api_url, e)
Send an event to the MPP coordinator.

        :param event: the type of event for coordinator to parse.
        
patroni/ha.py