There is bug with SONManipulator optimization here: https://github.com/mongodb/mongo-python-driver/blob/master/pymongo/database.py#L95

Due to this bug:

• we cannot create manipulator that isn't inherited from SONManipulator class. That's not so good.
• we cannot create two (or more) level manipulators inheritance hierarhy. For example this wouldn't work correct:

  from pymongo.son_manipulator import SONManipulator
  
  
  class ParentManipulator(SONManipulator):
      def transform_incoming(self, son, collection):
          son['collection_name'] = collection.name
          return son
  
      def transform_outgoing(self, son, collection):
          if 'collection_name' in son:
              del son['collection_name']
          return son
  
  
  class ChildManipulator(ParentManipulator):
      """ 
      It should work like ParentManipulator, but it wouldn't work at call :(
      """
      pass