You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: test_time.rs
    path of file: ./repos/incubator-teaclave-sgx-sdk/samplecode/unit-test/enclave/src
    
    the code of the file until where you have to start completion: use std::time::*;
use std::untrusted::time::{InstantEx, SystemTimeEx};

pub fn test_std_time() {
    macro_rules! assert_almost_eq {
        ($a:expr, $b:expr) => {{
            let (a, b) = ($a, $b);
            if a != b {
                let (a, b) = if a > b { (a, b) } else { (b, a) };
                assert!(a - Duration::new(0, 100) <= b);
            }
        }};
    }

    {
        let a = Instant::now();
        let b = Instant::now();
        assert!(b >= a);
    }

    {
        let a = Instant::now();
        a.elapsed();
    }

    {
        let a = Instant::now();
        let b = Instant::now();
        let dur = b.duration_since(a);
        assert_almost_eq!(b - dur, a);
        assert_almost_eq!(a + dur, b);

        let second = Duration::new(1, 0);
        assert_almost_eq!(a - second + second, a);
    }

    {
        let a = Instant::now();
        assert!((a - Duration::new(1, 0)).duration_since(a) == Duration::new(0, 0));
    }

    {
        let a = SystemTime::now();
        let b = SystemTime::now();
        match b.duration_since(a) {
            Ok(dur) if dur == Duration::new(0, 0) => {
                assert_almost_eq!(a, b);
            }
            Ok(dur) => {
                assert!(b > a);
                assert_almost_eq!(b - dur, a);
                assert_almost_eq!(a + dur, b);
            }
            Err(dur) => {
                let dur = dur.duration();
                assert!(a > b);
                assert_almost_eq!(b + dur, a);
                assert_almost_eq!(a - dur, b);
            }
        }

        let second = Duration::new(1, 0);
        assert_almost_eq!(a.duration_since(a - second).unwrap(), second);
        assert_almost_eq!(a.duration_since(a + second).unwrap_err().d
    
pub fn test_std_time() {
    macro_rules! assert_almost_eq {
        ($a:expr, $b:expr) => {{
            let (a, b) = ($a, $b);
            if a != b {
                let (a, b) = if a > b { (a, b) } else { (b, a) };
                assert!(a - Duration::new(0, 100) <= b);
            }
        }};
    }

    {
        let a = Instant::now();
        let b = Instant::now();
        assert!(b >= a);
    }

    {
        let a = Instant::now();
        a.elapsed();
    }

    {
        let a = Instant::now();
        let b = Instant::now();
        let dur = b.duration_since(a);
        assert_almost_eq!(b - dur, a);
        assert_almost_eq!(a + dur, b);

        let second = Duration::new(1, 0);
        assert_almost_eq!(a - second + second, a);
    }

    {
        let a = Instant::now();
        assert!((a - Duration::new(1, 0)).duration_since(a) == Duration::new(0, 0));
    }

    {
        let a = SystemTime::now();
        let b = SystemTime::now();
        match b.duration_since(a) {
            Ok(dur) if dur == Duration::new(0, 0) => {
                assert_almost_eq!(a, b);
            }
            Ok(dur) => {
                assert!(b > a);
                assert_almost_eq!(b - dur, a);
                assert_almost_eq!(a + dur, b);
            }
            Err(dur) => {
                let dur = dur.duration();
                assert!(a > b);
                assert_almost_eq!(b + dur, a);
                assert_almost_eq!(a - dur, b);
            }
        }

        let second = Duration::new(1, 0);
        assert_almost_eq!(a.duration_since(a - second).unwrap(), second);
        assert_almost_eq!(a.duration_since(a + second).unwrap_err().duration(), second);

        assert_almost_eq!(a - second + second, a);

        // A difference of 80 and 800 years cannot fit inside a 32-bit time_t
        //if !(cfg!(unix) && ::mem::size_of::<::libc::time_t>() <= 4) {
        //    let eighty_years = second * 60 * 60 * 24 * 365 * 80;
        //    assert_almost_eq!(a - eighty_years + eighty_years, a);
        //    assert_almost_eq!(a - (eighty_years * 10) + (eighty_years * 10), a);
        //}

        let one_second_from_epoch = UNIX_EPOCH + Duration::new(1, 0);
        let one_second_from_epoch2 =
            UNIX_EPOCH + Duration::new(0, 500_000_000) + Duration::new(0, 500_000_000);
        assert_eq!(one_second_from_epoch, one_second_from_epoch2);
    }

    {
        let a = SystemTime::now();
        drop(a.elapsed());
    }

    {
        let ts = SystemTime::now();
        let a = ts.duration_since(UNIX_EPOCH).unwrap();
        let b = ts.duration_since(UNIX_EPOCH - Duration::new(1, 0)).unwrap();
        assert!(b > a);
        assert_eq!(b - a, Duration::new(1, 0));

        let thirty_years = Duration::new(1, 0) * 60 * 60 * 24 * 365 * 30;

        // Right now for CI this test is run in an emulator, and apparently the
        // aarch64 emulator's sense of time is that we're still living in the
        // 70s.
        //
        // Otherwise let's assume that we're all running computers later than
        // 2000.
        if !cfg!(target_arch = "aarch64") {
            assert!(a > thirty_years);
        }

        // let's assume that we're all running computers earlier than 2090.
        // Should give us ~70 years to fix this!
        let hundred_twenty_years = thirty_years * 4;
        assert!(a < hundred_twenty_years);
    }
}