History of Mark::step 1 change

In crates/backdrop/src/mark.rs, lines 101–107 on 2bae995eb2f1232ed907223a93764a260522ed72604fe56f46bc8199c4c8f330. 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.