Skeleton of the recv() method for eventhandler

eventhandler2.rs

// Rest of the stuff remains the same.

fn recv(&mut self) {
    let receiver = self.nvim.session.start_event_loop_channel();

    for (event, values) in receiver {
        match Messages::from(event) {
            Messages::Add => {
                // do stuff
            }
            Messages::Multiply => {
                // do stuff
            }
            Messages::Unknown(uevent) => {
                // unknown event
            }
        }
    }
}