{"ast_node_type":"variable","tokens":[{"end":81,"kind":"keyword","start":0,"text":"let"}]}
                        let sig: ty::FnSig<'_> = tcx.liberate_late_bound_regions(
                        // `Self::Iter<'a>` is a GAT we want to gather any potential missing bounds from.
                            item_def_id.to_def_id(),