Function parse_page_annotations 

pub fn parse_page_annotations(
    resolver: &Resolver<'_>,
    pages: &[PageInfo],
    page_index: usize,
    sink: &WarningSink,
) -> Vec<Annotation>

Parse all annotations on a page from its PageInfo::annots list.

Skips annotations missing the required /Rect field; the skipped entry produces a ParseWarning in sink. Always returns a Vec (possibly empty).