You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: server.rs
    path of file: ./repos/examples/websockets/chat-tcp/src
    
    the code of the file until where you have to start completion: //! `ChatServer` is an actor. It maintains list of connection client session.
//! And manages available rooms. Peers send messages to other peers in same
//! r
    
    fn handle(&mut self, msg: Disconnect, _: &mut Context<Self>) {
        println!("Someone disconnected");

        let mut rooms: Vec<String> = Vec::new();

        // remove address
        if self.sessions.remove(&msg.id).is_some() {
            // remove session from all rooms
            for (name, sessions) in &mut self.rooms {
                if sessions.remove(&msg.id) {
                    rooms.push(name.to_owned());
                }
            }
        }
        // send message to other users
        for room in rooms {
            self.send_message(&room, "Someone disconnected", 0);
        }
    }