@Nonnull
    Lock getLock(@Nonnull final String roomName)
    {
        Log.trace("Obtaining lock for room '{}' of service '{}'", roomName, serviceName);
        return ROOM_CACHE.getLock(roomName);
    }
Generates a mutex object that controls cluster-wide access to a MUCRoom instance that represents the room in this
service identified by the provided name.

The lock, once returned, is not acquired/set.

@param roomName Name of the room for which to return a lock.
@return The lock (which has not been set yet).
xmppserver/src/main/java/org/jivesoftware/openfire/muc/spi/LocalMUCRoomManager.java