History of Mark::step 1 change

In crates/backdrop/src/mark.rs, lines 101–107 on 5caa65fd51e70be4b6320a97bb81662d8607a96797ea4dd3cd7e5ba4732702e5. 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.