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: client.rs
    path of file: ./repos/actix-web/awc/examples
    
    the code of the file until where you have to start completion: use std::error::Error as StdError;

#[tokio::main]

    
async fn main() -> Result<(), Box<dyn StdError>> {
    env_logger::init_from_env(env_logger::Env::new().default_filter_or("info"));

    // construct request builder
    let client = awc::Client::new();

    // configure request
    let request = client
        .get("https://www.rust-lang.org/")
        .append_header(("User-Agent", "Actix-web"));

    println!("Request: {:?}", request);

    let mut response = request.send().await?;

    // server response head
    println!("Response: {:?}", response);

    // read response body
    let body = response.body().await?;
    println!("Downloaded: {:?} bytes", body.len());

    Ok(())
}