Function shrink_sequence_by_removing 

pub fn shrink_sequence_by_removing<P, S, A>(
    calls_len: usize,
    run: &mut ShrinkRun,
    should_stop: S,
    on_attempt: A,
    predicate: P,
) -> SequenceShrink
where
    P: FnMut(&SequenceShrink) -> Option<bool>,
    S: FnMut() -> bool,
    A: FnMut(),

Shared sequence shrinker. Tries to drop each call; predicate decides whether the candidate should be accepted, rejected, or skipped without spending a replay attempt.