Add type hints For eth/utils module

Author: Bhargavasomu

eth/beacon/aggregation.py

@@ -6,7 +6,6 @@
     pipe
 )
 
-
 from eth_typing import (
     Hash32,
 )
@@ -62,7 +61,7 @@ def verify_votes(
 def aggregate_votes(bitfield: bytes,
                     sigs: Iterable[bytes],
                     voting_sigs: Iterable[bytes],
-                    voting_committee_indices: Iterable[int]) -> Tuple[bytes, Tuple[int]]:
+                    voting_committee_indices: Iterable[int]) -> Tuple[bytes, Tuple[int, int]]:
     """
     Aggregate the votes.
     """

eth/chains/base.py

@@ -40,6 +40,9 @@
     iterate,
     take,
 )
+from mypy_extensions import (
+    TypedDict,
+)
 
 from eth.db.backends.base import BaseAtomicDB
 from eth.db.chain import (
@@ -105,11 +108,13 @@
     from eth.vm.base import BaseVM  # noqa: F401
 
 
-# Mapping from address to account state.
-# 'balance', 'nonce' -> int
-# 'code' -> bytes
-# 'storage' -> Dict[int, int]
-AccountState = Dict[Address, Dict[str, Union[int, bytes, Dict[int, int]]]]
+AccountDetails = TypedDict('AccountDetails',
+                           {'balance': int,
+                            'nonce': int,
+                            'code': bytes,
+                            'storage': Dict[int, int]
+                            })
+AccountState = Dict[Address, AccountDetails]
 
 
 class BaseChain(Configurable, ABC):

eth/estimators/__init__.py

@@ -1,12 +1,14 @@
 import os
-from typing import Callable
+from typing import (
+    Any,
+)
 
 from eth.utils.module_loading import (
     import_string,
 )
 
 
-def get_gas_estimator() -> Callable:
+def get_gas_estimator() -> Any:
     import_path = os.environ.get(
         'GAS_ESTIMATOR_BACKEND_FUNC',
         'eth.estimators.gas.binary_gas_search_intrinsic_tolerance',