pub fn ensure_appearances(doc: &mut Document) -> Result<usize, AnnotBuildError>Expand description
Give every flattenable annotation without one a default appearance.
flatten_annotations only paints annotations that carry /AP /N; this
pass runs first so annotations without an appearance flatten too instead
of silently staying live. Widget and link annotations are left alone, as
are subtypes the builder cannot draw. Returns how many appearances were
added.