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: process_issue_42.rs
    path of file: ./repos/tokio/tokio/tests
    
    the code of the file until where you have to start completion: #![warn(rust_2018_idioms)]
#![cfg(feature = "full")]
#![cfg(unix)]

use futures::future::join_all;
use std::process::Stdio;
use tokio::process::Command;
use tokio::task;

#[tokio::test]
async fn issue_42() {
    // We spawn a many batches of processes which should exit at roughly the
    // same time (modulo OS scheduling delays), t
    
async fn issue_42() {
    // We spawn a many batches of processes which should exit at roughly the
    // same time (modulo OS scheduling delays), to make sure that consuming
    // a readiness event for one process doesn't inadvertently starve another.
    // We then do this many times (in parallel) in an effort to stress test the
    // implementation to ensure there are no race conditions.
    // See alexcrichton/tokio-process#42 for background
    let join_handles = (0..10usize).map(|_| {
        task::spawn(async {
            let processes = (0..10usize).map(|i| {
                let mut child = Command::new("echo")
                    .arg(format!("I am spawned process #{}", i))
                    .stdin(Stdio::null())
                    .stdout(Stdio::null())
                    .stderr(Stdio::null())
                    .kill_on_drop(true)
                    .spawn()
                    .unwrap();

                async move { child.wait().await }
            });

            join_all(processes).await;
        })
    });

    join_all(join_handles).await;
}