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: git_auth.rs
    path of file: ./repos/cargo/tests/testsuite
    
    the code of the file until where you have to start completion: //! Tests for git authentication.

use std::collections::HashSet;
use std::io::prelude::*;
use std::io::BufReader;
use std::net::{SocketAddr, TcpListener};
use std::sync::atomic::{AtomicUsize, Ordering::SeqCst};
use std::sync::Arc;
use std::thread::{self, JoinHandle};

use cargo_test_support::git::cargo_uses_gitoxide;
use cargo_test_support::paths;
use cargo_test_support::{basic_manifest, project};

fn setup_failed_auth_test() -> (SocketAddr, JoinHandle<()>, Arc<AtomicUsize>) {
    let server = TcpListener::bind("127.0.0.1:0").unwrap();
    let addr = server.local_addr().unwrap();

    fn headers(rdr: &mut dyn BufRead) -> HashSet<String> {
        let valid = ["GET", "Authorization", "Accept"];
        rdr.lines()
            .map(|s| s.unwrap())
            .take_while(|s| s.len() > 2)
            .map(|s| s.trim().to_string())
            .filter(|s| valid.iter().any(|prefix| s.starts_with(*prefix)))
            .col
    
fn https_something_happens() {
    let server = TcpListener::bind("127.0.0.1:0").unwrap();
    let addr = server.local_addr().unwrap();
    let t = thread::spawn(move || {
        let mut conn = server.accept().unwrap().0;
        drop(conn.write(b"1234"));
        drop(conn.shutdown(std::net::Shutdown::Write));
        drop(conn.read(&mut [0; 16]));
    });

    let p = project()
        .file(
            "Cargo.toml",
            &format!(
                r#"
                    [package]
                    name = "foo"
                    version = "0.0.1"
                    edition = "2015"
                    authors = []

                    [dependencies.bar]
                    git = "https://127.0.0.1:{}/foo/bar"
                "#,
                addr.port()
            ),
        )
        .file("src/main.rs", "")
        .file(
            ".cargo/config.toml",
            "[net]
             retry = 0
            ",
        )
        .build();

    p.cargo("check -v")
        .with_status(101)
        .with_stderr_contains(&format!(
            "[UPDATING] git repository `https://{addr}/foo/bar`"
        ))
        .with_stderr_contains(&format!(
            "\
Caused by:
  {errmsg}
",
            errmsg = if cargo_uses_gitoxide() {
                "[..]SSL connect error [..]"
            } else if cfg!(windows) {
                "[..]failed to send request: [..]"
            } else if cfg!(target_os = "macos") {
                // macOS is difficult to tests as some builds may use Security.framework,
                // while others may use OpenSSL. In that case, let's just not verify the error
                // message here.
                "[..]"
            } else {
                "[..]SSL error: [..]"
            }
        ))
        .run();

    t.join().ok().unwrap();
}