diff --git a/bidict/_common.py b/bidict/_common.py
index 4fcaca5..f3e9106 100644
--- a/bidict/_common.py
+++ b/bidict/_common.py
@@ -52,6 +52,7 @@ class DuplicationBehavior(_marker):
 
     """
 
+
 DuplicationBehavior.RAISE = RAISE = DuplicationBehavior('RAISE')
 DuplicationBehavior.OVERWRITE = OVERWRITE = DuplicationBehavior('OVERWRITE')
 DuplicationBehavior.IGNORE = IGNORE = DuplicationBehavior('IGNORE')
diff --git a/tests/test_polymorphic_equality.py b/tests/test_polymorphic_equality.py
index 1e60599..2efdc24 100644
--- a/tests/test_polymorphic_equality.py
+++ b/tests/test_polymorphic_equality.py
@@ -7,6 +7,7 @@ from itertools import product
 class dictsubclass(dict):
     pass
 
+
 d = dict(H='hydrogen', He='helium')
 c = Counter(d)
 o = OrderedDict(d)