in time/src/lib.rs [230:245]
fn basic() {
let now = Instant::<Nanoseconds<u64>>::now();
std::thread::sleep(std::time::Duration::new(1, 0));
let elapsed = now.elapsed();
assert!(elapsed.as_secs_f64() >= 1.0);
assert!(elapsed.as_secs() >= 1);
assert!(elapsed.as_nanos() >= NANOS_PER_SEC);
let t0 = Instant::<Nanoseconds<u64>>::recent();
std::thread::sleep(std::time::Duration::new(1, 0));
assert_eq!(Instant::<Nanoseconds<u64>>::recent(), t0);
refresh_clock();
let t1 = Instant::<Nanoseconds<u64>>::recent();
assert!((t1 - t0).as_secs_f64() >= 1.0);
assert!((t1 - t0).as_secs() >= 1);
}