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: return_object.rs
    path of file: ./repos/FireDBG.for.Rust/debugger/testcases
    
    the code of the file until where you have to start completion: #[derive(Debug)]
struct Car {
    brand: &'static str,
    engine: Engine,
    gearbox: Gearbox,
}

#[derive(Debug)]
struct Engine {
    con
    
fn main() {
    let man = create_manual_car();
    println!("{man:?}");

    let car = Car {
        brand: "Nil",
        engine: Engine {
            config: EngineConfig::Inline { i: 0 },
            pistons: vec![],
        },
        gearbox: Gearbox::Automatic,
    };

    let auto = create_auto_car();
    println!("{auto:?}");

    let what_car = choose_a_car_for_me(true, &auto, &man);
    println!("{what_car:?}");

    let what_car_again = choose_a_car_for_me(false, &auto, &man);
    println!("{what_car_again:?}");
}