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: hyper-client.rs
    path of file: ./repos/smol/examples
    
    the code of the file until where you have to start completion: //! An HTTP+TLS client based on `hyper` and `async-native-tls`.
//!
//! Run with:
//!
//! ```
//! cargo run --example hyper-client
//! ```

use std::convert::TryInto;
use std::pin::Pin;
use std::task::{Context, Poll};

use anyhow::{bail, Context as _, Result};
use async_native_tls::TlsStream;
use http_body_util::{BodyStream, Empty};
use hyper::body::Incoming;
use hyper::{Request, Response};
use macro_rules_attribute::apply;
use smol::{io, net::TcpStream, prelude::*, Executor};
use smol_hyper::rt::FuturesIo;
use smol_macros::main;

/// Sends a request and fetches the response.
async fn fetch(
    ex: &Executor<'static>,
 
    
async fn main(ex: &Executor<'static>) -> Result<()> {
    // Create a request.
    let url: hyper::Uri = "https://www.rust-lang.org".try_into()?;
    let req = Request::builder()
        .header(
            hyper::header::HOST,
            url.authority().unwrap().clone().as_str(),
        )
        .uri(url)
        .body(Empty::new())?;

    // Fetch the response.
    let resp = fetch(ex, req).await?;
    println!("{:#?}", resp);

    // Read the message body.
    let body: Vec<u8> = BodyStream::new(resp.into_body())
        .try_fold(Vec::new(), |mut body, chunk| {
            if let Some(chunk) = chunk.data_ref() {
                body.extend_from_slice(chunk);
            }
            Ok(body)
        })
        .await?;
    println!("{}", String::from_utf8_lossy(&body));

    Ok(())
}