pub fn first_difference(
parts: &[(&str, &str, &str)],
recorded_items: &[String],
sent_items: &[String],
) -> Option<String>Expand description
The first part in which sent differs from recorded, as
batch_id_reuse names it. parts are the role’s named parts in the
order it checks them, each (name, recorded, sent); then the item count
(items) and the first differing item (items[i]). None when every
part and item is the same, which makes the re-send a replay.