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: mod.rs
    path of file: ./repos/salvo/crates/core/src/conn/openssl
    
    the code of the file until where you have to start completion: //! OpensslListener and utils.
mod config;
pub use config::{Keycert, OpensslConfig, SslAcceptorBuilder};

mod listener;
pub use listener::{OpensslAcceptor, OpensslListener};

#[cfg(test)]
mod tests {
    use std::pin::Pin;
    use std::sync::Arc;

    use openssl::ssl::{SslConnector, SslMethod};
    use tokio::io::{AsyncReadExt, AsyncWriteExt};
    use tokio::net::TcpStream;
    use tokio_openssl::SslStream;

    use super::*;
    use crate::conn::{Accepted, Acceptor, Listener, TcpListener};
    use crat
    
    async fn test_openssl_listener() {
        let mut acceptor = TcpListener::new("127.0.0.1:0")
            .openssl(OpensslConfig::new(
                Keycert::new()
                    .key_from_path("certs/key.pem")
                    .unwrap()
                    .cert_from_path("certs/cert.pem")
                    .unwrap(),
            ))
            .bind()
            .await;
        let addr = acceptor.holdings()[0].local_addr.clone().into_std().unwrap();

        tokio::spawn(async move {
            let mut connector = SslConnector::builder(SslMethod::tls()).unwrap();
            connector.set_ca_file("certs/chain.pem").unwrap();

            let ssl = connector
                .build()
                .configure()
                .unwrap()
                .into_ssl("testserver.com")
                .unwrap();

            let stream = TcpStream::connect(addr).await.unwrap();
            let mut tls_stream = SslStream::new(ssl, stream).unwrap();
            Pin::new(&mut tls_stream).connect().await.unwrap();

            tls_stream.write_i32(518).await.unwrap();
        });

        let Accepted { mut conn, .. } = acceptor.accept(Arc::new(SteadyFusewire)).await.unwrap();
        assert_eq!(conn.read_i32().await.unwrap(), 518);
    }