History of plural 1 change

In src/cli/format.rs, lines 19–21 on e4b8bcf04a868996db3527329e593f19e4932f9f668b6d03add86e8a48073e6c. 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.