{"ast_node_type":"variable","tokens":[{"end":83,"kind":"keyword","start":0,"text":"let"}]}
                        let base_generic_arg = identity_args[param_index as usize];
                        let base_ty = Ty::new_adt(self.infcx.tcx, *adt, identity_args);
                        let adt_desc = adt.descr();