1pub fn add(left: usize, right: usize) -> usize { 2 left + right 3} 4 5#[cfg(test)] 6mod tests { 7 use super::*; 8 9 #[test] 10 fn it_works() { 11 let result = add(2, 2); 12 assert_eq!(result, 4); 13 } 14}