History of Mark::step 1 change

In crates/backdrop/src/mark.rs, lines 101–107 on f6529a2fb9db17410960eca0baa6f0c4fc345a5e3b9ae58ada24f14d470f27ed. 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.