use std::cmp;
let result = cmp::max_by_key(3, -2, |x: &i32| x.abs());
assert_eq!(result, 3);
let result = cmp::max_by_key(1, -2, |x: &i32| x.abs());
assert_eq!(result, -2);
let result = cmp::max_by_key(1, -1, |x: &i32| x.abs());
assert_eq!(result, -1);