{"ast_node_type":"other","tokens":[{"end":53,"kind":"keyword","start":0,"text":"ty::Uint(UintTy::Usize)"}]}
                ty::Uint(UintTy::Usize) => "u5usize",
                ty::Uint(UintTy::U128) => "u4u128",
                _ => bug!("encode_ty: unexpected `{:?}`", ty.kind()),