fn matched_novel_lines(
lhs_mps: &[MatchedPos],
rhs_mps: &[MatchedPos],
) -> Vec<(Option<LineNumber>, Option<LineNumber>)>fn matched_novel_lines(
lhs_mps: &[MatchedPos],
rhs_mps: &[MatchedPos],
) -> Vec<(Option<LineNumber>, Option<LineNumber>)>