def set_synchronous_standby_names(self, value: Optional[str]) -> Optional[bool]:
        """Updates synchronous_standby_names and reloads if necessary.
        :returns: True if value was updated."""
        if value != self._server_parameters.get('synchronous_standby_names'):
            if value is None:
                self._server_parameters.pop('synchronous_standby_names', None)
            else:
                self._server_parameters['synchronous_standby_names'] = value
            if self._postgresql.state == PostgresqlState.RUNNING:
                self.write_postgresql_conf()
                self._postgresql.reload()
            return True
Updates synchronous_standby_names and reloads if necessary.
        :returns: True if value was updated.
patroni/postgresql/config.py