{"ast_node_type":"function","tokens":[{"end":92,"kind":"keyword","start":0,"text":"pub(super)"}]}
    pub(super) fn insert(&self, unique_type_id: UniqueTypeId<'tcx>, metadata: &'ll DIType) {
    /// fail if the mapping already exists.
        if self.unique_id_to_di_node.borrow_mut().insert(unique_type_id, metadata).is_some() {