History of Mark::step 1 change

In crates/backdrop/src/mark.rs, lines 101–107 on 6aedcd6c0ad2c07f478a4943554f038a7f629299e94f6662aba8ee4611c8a3b2. 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.