self.on["mongodb"].relation_broken: self._on_required_relation_broken,
self.on["ro"].relation_changed: self._on_config_changed,
self.on["ro"].relation_broken: self._on_required_relation_broken,
self.on["mongodb"].relation_broken: self._on_required_relation_broken,
self.on["ro"].relation_changed: self._on_config_changed,
self.on["ro"].relation_broken: self._on_required_relation_broken,