fn highlight_as_novel(
line_num: Option<LineNumber>,
lines: &[&str],
opposite_line_num: Option<LineNumber>,
lines_with_novel: &FxHashSet<LineNumber>,
) -> boolfn highlight_as_novel(
line_num: Option<LineNumber>,
lines: &[&str],
opposite_line_num: Option<LineNumber>,
lines_with_novel: &FxHashSet<LineNumber>,
) -> bool