diff --git a/solutions/object_oriented_design/call_center/call_center.py b/solutions/object_oriented_design/call_center/call_center.py
index 1a295053..799030df 100644
--- a/solutions/object_oriented_design/call_center/call_center.py
+++ b/solutions/object_oriented_design/call_center/call_center.py
@@ -9,6 +9,7 @@ class Rank(Enum):
     SUPERVISOR = 20
     DIRECTOR = 10
 
+
 class Employee(metaclass=ABCMeta):
 
     def __init__(self, employee_id, name, rank, call_center):