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: freight_train.rs
    path of file: ./repos/design-patterns-rust/behavioral/mediator/mediator-rc-refcell/trains
    
    the code of the file until where you have to start completion: use std::{cell::RefCell, rc::Rc};

use super::Train;
use crate::train_station::Mediator;

pub struct FreightTrain {
    name: String,
    mediator: Rc<RefCell<dyn Med
    
    fn arrive(&self) {
        if !self.mediator.borrow().notify_about_arrival(self) {
            println!("Freight train {}: Arrival blocked, waiting", self.name);
            return;
        }

        println!("Freight train {}: Arrived", self.name);
    }