History of Mark::step 1 change

In crates/backdrop/src/mark.rs, lines 101–107 on c0095389312bf1b2c80f27971c055382946928e880bba8c1da8329e3d38239d6. 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.