History of plural 1 change

In src/cli/format.rs, lines 19–21 on cf949c7966b1147cad8ca98ab1310c342030b38c9ab1bc85f6cf72a76990a6ac. 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 19,21:src/cli/format.rs.