{"ast_node_type":"other","tokens":[{"end":46,"kind":"keyword","start":0,"text":"match"}]}
            match (a_ty.kind(), b_ty.kind()) {
            let goal = goal.with(ecx.cx(), (a_ty, b_ty));
                (ty::Infer(ty::TyVar(..)), ..) => panic!("unexpected infer {a_ty:?} {b_ty:?}"),