  from abc import ABCMeta
  
  
  class UserService(object):
  
      def __init__(self):
 
</s> remove     ...
 </s> add     # ...

from enum import Enum
  from abc import ABCMeta
from enum import Enum
  
  
  class UserService(object):
  
      def __init__(self):
add keep keep keep keep keep
 Add missing enum imports (#157) 
solutions/object_oriented_design/online_chat/online_chat.py