History of Mark::step 1 change

In crates/backdrop/src/mark.rs, lines 101–107 on f87a74fffc8715b03636a4f59ff2a5ec4fe564a9f9c7521a03a1bfaf5fa04773. 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.