History of Mark::step 1 change

In crates/backdrop/src/mark.rs, lines 101–107 on 8bf3010760d73eb57dfeb99535f4eb3677f8d40a284e795c7f69a24e965b9b70. 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.