void main() {
    long l1 = getMillis();
    long l2 = getMillis();
    long l3 = getMillis();
    long l4 = getMillis();
    test(l1 <= l2 && l2 <= l3 && l3 <= l4);
    
    l1 = getNanos();
    l2 = getNanos();
    l3 = getNanos();
    l4 = getNanos();
    test(l1 < l2 && l2 < l3 && l3 < l4);
    
    Time time;
    long millis = getMillis();
    toTime(&time, millis);
    
    test(time.year >= 2021);
    test(time.month >= 0 && time.month <= 11);
    test(time.day >= 1 && time.day <= 31);
    test(time.hours >= 0 && time.hours <= 59);
    test(time.minutes >= 0 && time.minutes <= 59);
    test(time.seconds >= 0 && time.seconds <= 60);
    test(time.millis >= 0 && time.millis <= 999);
    
    test(millis == toMillis(&time));
}