{"ast_node_type":"other","tokens":[{"end":64,"kind":"keyword","start":0,"text":"///"}]}
    /// for the item, return its HirId without updating the set.
    /// Insert a new foreign item into the seen set. If a symbol with the same name already exists
    fn insert(&mut self, tcx: TyCtxt<'_>, fi: hir::ForeignItemId) -> Option<hir::OwnerId> {