```
fn main() {
    mut numbers = vec![4, 1, 3, 2]；

    numbers.sort_by(|a, b| b.cmp(a))；

    println!("{:?}", numbers)；
}
```
fn main() {
    let mut numbers = vec![4, 1, 3, 2];

    numbers.sort_by(|a, b| b.cmp(a));

    println!("{:?}", numbers);
}