private IOCallback findCallback(IOMessage message) throws SocketIOException {
		if ("".equals(message.getEndpoint()))
			return this;
		SocketIO socket = sockets.get(message.getEndpoint());
		if (socket == null) {
			throw new SocketIOException("Cannot find socket for '"
					+ message.getEndpoint() + "'");
		}
		return socket.getCallback();
	}
finds the corresponding callback object to an incoming message. Returns a
dummy callback if no corresponding callback can be found

@param message
           the message
@return the iO callback
@throws SocketIOException
src/io/socket/IOConnection.java