diff --git a/src/py_overload/__init__.py b/src/py_overload/__init__.py
index e5dc750..5410415 100644
--- a/src/py_overload/__init__.py
+++ b/src/py_overload/__init__.py
@@ -7,33 +7,28 @@ class AnnotationError(ValueError):
     pass
 
 
-
 class AnnotationErrors(AnnotationError):
     pass
 
 
-
 class InternalAnnotationError(Exception):
     pass
 
 
-
 class CastingError(TypeError):
     pass
 
 
-
 class OverloadError(TypeError):
     pass
 
 
-
 class AnnotationResolutionError(AnnotationError):
     _raise = False
 
 
 class Values(tuple):
-    'wrapper class in case of several value'
+    "wrapper class in case of several value"
     
     def __call__(self, val):
         return val in self