Try fix macos unit test failure
@@ -41,17 +41,29 @@ use crate::pipelines::transforms::group_by::AggregatorState;
///
/// For example:
///
-/// impl PolymorphicKeysHelper<NewHashMethod> for NewHashMethod {
-/// type State: NewHashMethodDataState;
+/// ```
+/// use common_datablocks::HashMethodSerializer;
+/// use bumpalo::Bump;
+/// use datafuse_query::common::HashTable;
+/// use common_datavalues::arrays::BinaryArrayBuilder;
+/// impl PolymorphicKeysHelper<HashMethodSerializer> for HashMethodSerializer {
+/// type State = SerializedKeysAggregatorState;
/// fn aggregate_state(&self) -> Self::State {
-/// NewHashMethodDataState::create()
+/// SerializedKeysAggregatorState {
+/// keys_area: Bump::new(),
+/// state_area: Bump::new(),
+/// data_state_map: HashTable::create(),
+/// }
/// }
///
-/// type ArrayBuilder: NewHashMethodArrayBuilder;
+/// type ArrayBuilder = SerializedKeysArrayBuilder;
/// fn state_array_builder(&self, capacity: usize) -> Self::ArrayBuilder {
-/// NewHashMethodArrayBuilder::create()
+/// SerializedKeysArrayBuilder {
+/// inner_builder: BinaryArrayBuilder::with_capacity(capacity),
+/// }
/// }
/// }
+/// ```
///
pub trait PolymorphicKeysHelper<Method: HashMethod> {
type State: AggregatorState<Method>;
