History of Mark::step 1 change

In crates/backdrop/src/mark.rs, lines 101–107 on c4027e038d2533aa595eef44c4c8e7b9c6ee08efed3b65a9d76a4a14aa5ff38c. Every change that wrote or deleted one of these lines, or deleted a line from between them. Exact, because each line keeps its identity across edits; edits elsewhere in the file are not here. Also: oxy log -L 101,107:crates/backdrop/src/mark.rs.