'Unlock a previously locked server.'

def unlock(self):

    cmd = {'fsyncUnlock': 1}
    with self._socket_for_writes() as sock_info:
        if (sock_info.max_wire_version >= 4):
            try:
                sock_info.command('admin', cmd)
            except OperationFailure as exc:
                if (exc.code != 125):
                    raise
        else:
            helpers._first_batch(sock_info, 'admin', '$cmd.sys.unlock', {}, (-1), True, self.codec_options, ReadPreference.PRIMARY, cmd, self._event_listeners)
