{"ast_node_type":"other","tokens":[{"end":98,"kind":"keyword","start":0,"text":"field_types.iter().next_back().unwrap().1.clone().substitute(Interner,"}]}
                    field_types.iter().next_back().unwrap().1.clone().substitute(Interner, subst);
                let last_field_ty =
                let sized_part_size =