Fix type hint

Author: hwwhww

eth/beacon/helpers.py

@@ -6,6 +6,7 @@
     Any,
     Iterable,
     Sequence,
+    Tuple,
     TYPE_CHECKING,
 )
 
@@ -214,7 +215,7 @@ def get_attestation_indices(crystallized_state: 'CrystallizedState',
             yield from shard_and_committee.committee
 
 
-def get_active_validator_indices(validators: Sequence['ValidatorRecord']) -> Iterable[int]:
+def get_active_validator_indices(validators: Sequence['ValidatorRecord']) -> Tuple[int, ...]:
     """
     Gets indices of active validators from ``validators``.
     """

eth/beacon/utils/random.py

@@ -3,6 +3,7 @@
     Any,
     Iterable,
     Sequence,
+    Tuple,
     TypeVar,
 )
 
@@ -85,7 +86,7 @@ def shuffle(values: Sequence[Any],
     return output
 
 
-def split(values: Sequence[TItem], split_count: int) -> Iterable[Any]:
+def split(values: Sequence[TItem], split_count: int) -> Tuple[Any, ...]:
     """
     Returns the split ``values`` in ``split_count`` pieces in protocol.
     Spec: https://github.com/ethereum/eth2.0-specs/blob/70cef14a08de70e7bd0455d75cf380eb69694bfb/specs/core/0_beacon-chain.md#helper-functions  # noqa: E501