History of Mark::step 1 change

In crates/backdrop/src/mark.rs, lines 101–107 on ab2d8b40f9f434845a237aa17fa9d759c9103c8a3e3e1aced1962dc6767e2f58. 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.