diff --git a/cow_py/core/constants.py b/cow_py/core/constants.py
index f71d666..29ca7c3 100644
--- a/cow_py/core/constants.py
+++ b/cow_py/core/constants.py
@@ -1,34 +1,41 @@
+from enum import Enum
 from typing import Dict
 from .chains import Chain
 
+"""
+This module contains constants and functions related to the CoW Protocol. It provides mappings of 
+the main CoW contract addresses to CoW's supported networks.
+"""
+
 BUY_ETH_ADDRESS = "0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE"
 
-VAULT_RELAYER = "0xC92E8bdf79f0507f65a392b0ab4667716BFE0110"
-COMPOSABLE_COW = "0xfdaFc9d1902f4e0b84f65F49f244b32b31013b74"
-SETTLEMENT_CONTRACT = "0x9008D19f58AAbD9eD0D60971565AA8510560ab41"
-EXTENSIBLE_FALLBACK_HANDLER = "0x2f55e8b20D0B9FEFA187AA7d00B6Cbe563605bF5"
 
+class CowContractAddress(Enum):
+    VAULT_RELAYER = "0xC92E8bdf79f0507f65a392b0ab4667716BFE0110"
+    COMPOSABLE_COW = "0xfdaFc9d1902f4e0b84f65F49f244b32b31013b74"
+    SETTLEMENT_CONTRACT = "0x9008D19f58AAbD9eD0D60971565AA8510560ab41"
+    EXTENSIBLE_FALLBACK_HANDLER = "0x2f55e8b20D0B9FEFA187AA7d00B6Cbe563605bF5"
+
+
+def map_address_to_supported_networks(address) -> Dict[Chain, str]:
+    """
+    Maps a given address to all supported networks.
 
-def map_address_to_supported_networks(address: str) -> Dict[Chain, str]:
+    :param address: The address to be mapped.
+    :return: A dictionary mapping the address to each supported chain.
+    """
     return {chain_id: address for chain_id in Chain}
 
 
-""" An object containing the addresses of the CoW Protocol settlement contracts for each supported chain. """
 COW_PROTOCOL_SETTLEMENT_CONTRACT_CHAIN_ADDRESS_MAP = map_address_to_supported_networks(
-    SETTLEMENT_CONTRACT
+    CowContractAddress.SETTLEMENT_CONTRACT
 )
-
-""" An object containing the addresses of the CoW Protocol Vault relayer contracts for each supported chain. """
 COW_PROTOCOL_VAULT_RELAYER_CHAIN_ADDRESS_MAP = map_address_to_supported_networks(
-    VAULT_RELAYER
+    CowContractAddress.VAULT_RELAYER
 )
-
-""" An object containing the addresses of the `ExtensibleFallbackHandler` contracts for each supported chain.   """
 EXTENSIBLE_FALLBACK_HANDLER_CONTRACT_CHAIN_ADDRESS_MAP = (
-    map_address_to_supported_networks(EXTENSIBLE_FALLBACK_HANDLER)
+    map_address_to_supported_networks(CowContractAddress.EXTENSIBLE_FALLBACK_HANDLER)
 )
-
-""" An object containing the addresses of the `ComposableCow` contracts for each supported chain. """
 COMPOSABLE_COW_CONTRACT_CHAIN_ADDRESS_MAP = map_address_to_supported_networks(
-    COMPOSABLE_COW
+    CowContractAddress.COMPOSABLE_COW
 )
diff --git a/cow_py/subgraphs/base/client.py b/cow_py/subgraphs/base/client.py
index 20dce3e..a9e82bf 100644
--- a/cow_py/subgraphs/base/client.py
+++ b/cow_py/subgraphs/base/client.py
@@ -7,6 +7,7 @@
 
 import httpx
 
+
 class GraphQLError(Exception):
     pass
 
diff --git a/tests/core/test_cow_error.py b/tests/core/test_cow_error.py
index d97e8ea..6f09344 100644
--- a/tests/core/test_cow_error.py
+++ b/tests/core/test_cow_error.py
@@ -1,4 +1,3 @@
-import pytest
 from cow_py.core.cow_error import (
     CowError,
 )  # Adjust the import path according to your project structure