diff --git a/fin_defs/__init__.py b/fin_defs/__init__.py
index f5223cc..a387a41 100644
--- a/fin_defs/__init__.py
+++ b/fin_defs/__init__.py
@@ -16,11 +16,11 @@ Defined hierarchy:
   - `Commodity`
 """
 
+import abc
 import dataclasses
 import datetime
 import re
 from decimal import Decimal
-import abc
 
 import enforce_typing
 
@@ -176,6 +176,7 @@ class FiatCurrency(Currency):
     def raw_short_name(self) -> str:
         return self.iso_code
 
+
 @enforce_typing.enforce_types
 @dataclasses.dataclass(frozen=True, eq=True)
 class CryptoCurrency(Currency):
@@ -192,6 +193,7 @@ class CryptoCurrency(Currency):
     def raw_short_name(self) -> str:
         return self.ccxt_symbol
 
+
 @enforce_typing.enforce_types
 @dataclasses.dataclass(frozen=True, eq=True)
 class Stock(Asset):
@@ -225,6 +227,7 @@ class Index(Asset):
     def raw_short_name(self) -> str:
         return self.ticker
 
+
 @enforce_typing.enforce_types
 @dataclasses.dataclass(frozen=True, eq=True)
 class Commodity(Asset):
@@ -236,7 +239,7 @@ class Commodity(Asset):
             raise ValueError(msg)
 
     def raw_short_name(self) -> str:
-        return self.alpha_vantage_id # TODO
+        return self.alpha_vantage_id  # TODO
 
 
 Commodity.CRUDE_OIL_WTI = Commodity('WTI')
diff --git a/test/test_ids.py b/test/test_ids.py
index 85ac0b2..a71c807 100644
--- a/test/test_ids.py
+++ b/test/test_ids.py
@@ -2,11 +2,15 @@ import pytest
 
 import fin_defs
 
+
 @pytest.mark.parametrize('asset', fin_defs.WELL_KNOWN_SYMBOLS.values())
 def test_to_from_string_id(asset: fin_defs.Asset):
     assert fin_defs.Asset.from_string_id(asset.to_string_id()) == asset
+
+
 import fin_defs
 
+
 @pytest.mark.parametrize('asset', fin_defs.WELL_KNOWN_SYMBOLS.values())
 def test_to_from_polygon_id(asset: fin_defs.Asset):
     assert fin_defs.Asset.from_polygon_id(asset.to_polygon_id()) == asset