History of Mark::step 1 change

In crates/backdrop/src/mark.rs, lines 101–107 on 8f1d76f4169ab0ad61c184b6889680cfe0da3d6b626f1b29f58e1b33a7903319. 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.