History of plural 1 change

In src/cli/format.rs, lines 19–21 on 84b9e9ac0ab48016b387bc5f5964a76b9ca9ce8a38dd190115000525e7f14e8d. 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.