Sender void void Sender::Ack (bool ok) Ack bool ok Acknowledgement from server Sender class. Can be used to send a command to the server. The receiver will acknowledge the command by calling Ack(). Sender,Receiver; Sender->Receiver [label="Command()", URL="\ref Receiver::Command()"]; Sender<-Receiver [label="Ack()", URL="\ref Ack()", ID="1"]; Sender Ack