194     pub fn num_microseconds(&self) -> Option<i64> {  in num_microseconds()  method
524         assert_eq!(Duration::zero().num_microseconds(), Some(0));  in test_duration_num_microseconds()
525         assert_eq!(Duration::microseconds(1).num_microseconds(), Some(1));  in test_duration_num_microseconds()
526         assert_eq!(Duration::microseconds(-1).num_microseconds(), Some(-1));  in test_duration_num_microseconds()
527         assert_eq!(Duration::nanoseconds(999).num_microseconds(), Some(0));  in test_duration_num_microseconds()
528         assert_eq!(Duration::nanoseconds(1001).num_microseconds(), Some(1));  in test_duration_num_microseconds()
529         assert_eq!(Duration::nanoseconds(-999).num_microseconds(), Some(0));  in test_duration_num_microseconds()
530         assert_eq!(Duration::nanoseconds(-1001).num_microseconds(), Some(-1));  in test_duration_num_microseconds()
531         assert_eq!(Duration::microseconds(i64::MAX).num_microseconds(), Some(i64::MAX));  in test_duration_num_microseconds()
532         assert_eq!(Duration::microseconds(i64::MIN).num_microseconds(), Some(i64::MIN));  in test_duration_num_microseconds()
533         assert_eq!(MAX.num_microseconds(), None);  in test_duration_num_microseconds()
534         assert_eq!(MIN.num_microseconds(), None);  in test_duration_num_microseconds()
539             Duration::days(i64::MAX / MICROS_PER_DAY).num_microseconds(),  in test_duration_num_microseconds()
543             Duration::days(i64::MIN / MICROS_PER_DAY).num_microseconds(),  in test_duration_num_microseconds()
546         assert_eq!(Duration::days(i64::MAX / MICROS_PER_DAY + 1).num_microseconds(), None);  in test_duration_num_microseconds()
547         assert_eq!(Duration::days(i64::MIN / MICROS_PER_DAY - 1).num_microseconds(), None);  in test_duration_num_microseconds()