Function collect_plain 

pub fn collect_plain(
    target: &HttpTarget,
    value: &str,
    n: usize,
    on_progress: impl FnMut(usize, usize),
) -> PlainSamples

Collects n consecutive measurements of the same request. Unlike run_interleaved, it doesn’t abort on packet loss — it just counts it: in doctor mode, the loss rate itself is part of the diagnosis, not a reason to stop.