pub fn assert_close(a: f64, b: f64) {
let diff = (a - b).abs();
assert!(diff < 1e-10, "{} != {}", a, b);
}
pub fn run_tests() {
assert_close(super::ops::add(2.0, 3.0), 5.0);
assert_close(super::ops::subtract(10.0, 3.0), 7.0);
assert_close(super::ops::multiply(4.0, 5.0), 20.0);
assert_close(super::ops::divide(15.0, 3.0), 5.0);
}