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: version_02.rs
    path of file: ./repos/rust-farm/handson/oop_practice/src
    
    the code of the file until where you have to start completion: /*
   Bu versiyonda ise entity nesneleri container görevi üstlenen bir veri yapısında saklanır.
   Enum kullanımı terk edilmiştir.
*/
use std::time::Instant;

fn main() {
  
    
fn main() {
    let game = prepare_objects();
    let start = Instant::now();
    let mut total_cost = 0.;
    for _ in 0..10 {
        total_cost = game.calc_total_cost();
    }
    let duration = start.elapsed() / 10 as u32;
    println!(
        "Total cost is {total_cost}. Total duration is {:?}",
        duration
    );
}