use std::convert::Infallible; use git_features::parallel::InOrderIter; #[test]fn in_order_stays_in_order() {    assert_eq!(        InOrderIter::from(vec![Ok::<_, Infallible>((0usize, 'a')), Ok((1, 'b')), Ok((2, 'c'))].into_iter())            .collect::<Result<Vec<_>, _>>()            .expect("infallible"),        vec!['a', 'b', 'c']    )} #[test]fn out_of_order_items_are_held_until_the_sequence_is_complete() {    assert_eq!(        InOrderIter::from(            vec![                Ok::<_, Infallible>((2usize, 'c')),                Ok((1, 'b')),                Ok((0, 'a')),                Ok((3, 'd'))            ]            .into_iter()        )        .collect::<Result<Vec<_>, _>>()        .expect("infallible"),        vec!['a', 'b', 'c', 'd']    )} #[test]fn in_sequence_errors_immediately_trigger_a_fuse() {    let mut iter = InOrderIter::from(vec![Ok::<_, &'static str>((0usize, 'a')), Err("err"), Ok((1, 'b'))].into_iter());    assert_eq!(iter.next(), Some(Ok('a')));    assert_eq!(iter.next(), Some(Err("err")));    assert_eq!(        iter.next(),        None,        "fuse should have triggered so we don't see anything else"    );} #[test]fn out_of_sequence_errors_immediately_trigger_a_fuse() {    let mut iter = InOrderIter::from(vec![Ok::<_, &'static str>((1usize, 'b')), Err("err"), Ok((0, 'a'))].into_iter());    assert_eq!(iter.next(), Some(Err("err")));    assert_eq!(        iter.next(),        None,        "fuse should have triggered so we don't see anything else"    );}