// Tests are important to ensure that your code does what you think it should
// do.
fnis_even(n:i64)->bool{
n %2==0}fnmain(){// You can optionally experiment here.
}#[cfg(test)]modtests{// When writing unit tests, it is common to import everything from the outer
// module (`super`) using a wildcard.
usesuper::*;#[test]fnyou_can_assert(){assert!(is_even(0));assert!(!is_even(-1));// ^ You can assert `false` using the negation operator `!`.
}}