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: prop_children_broadcast.rs
    path of file: ./repos/bastion/src/bastion/tests
    
    the code of the file until where you have to start completion: use bastion::prelude::*;
use proptest::prelude::*;
use std::sync::Once;

static START: Once = Once::new();

#[cfg(feature = "tokio-runtime")]
mod tokio_proptests {
    use super::*;
    proptest! {
        #![proptest_config(ProptestConfig::with_cases(1_000))]
     
    
fn test_with_message(message: String) {
    START.call_once(|| {
        Bastion::init();
    });
    Bastion::start();

    if let Ok(_chrn) = Bastion::children(|children: Children| {
        children.with_exec(move |ctx: BastionContext| {
            async move {
                msg! { ctx.recv().await?,
                    ref _msg: &'static str => {};
                    // This won't happen because this example
                    // only "asks" a `&'static str`...
                    _: _ => {};
                }

                Ok(())
            }
        })
    }) {
        let message: &'static str = Box::leak(message.into_boxed_str());
        Bastion::broadcast(message).expect("broadcast failed");
    }
}