Function parse_annotations 

pub fn parse_annotations<S>(
    annots_obj: &Object,
    store: &ObjectStore<S>,
) -> Result<Vec<Annotation>, DocError>
where
    S: PdfSource,

Parse all annotations from a page’s /Annots array.

The annots_obj should be the value of the /Annots key from the page dictionary — either a direct array or an indirect reference to one.