History of Mark::step 1 change

In crates/backdrop/src/mark.rs, lines 101–107 on 16ee5d19d22064bdc73a1e69524dada66100b0d2ae068d40f7814e1f3d5d81ba. 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.