old_contents: import logging
  from asyncio_mongo._bson import ObjectId
  from wolverine.module.service import MicroService
  
  logger = logging.getLogger(__name__)
  
  
  class MongoService(MicroService):
  
      def __init__(self, app):
          super(MongoService, self).__init__(app, 'mongo-demo')
          self.version = 2
  
      def read(self, data):
  
          obj_id = data.get('id', None)
          db_name = data.get('db', None)
          db = getattr(self.app.mongo, db_name)
          col_name = data.get('collection', None)
          if db:
              collection = getattr(db, col_name)
              if obj_id and collection:
                  doc = yield from collection.find_one({'_id': ObjectId(obj_id)})
                  logger.debug('doc: ' + str(doc))
                  return fix_id(doc)
          return None
  
  
  def fix_id(doc):
      """
      Replaces the _id value with id
      @:param document: mongo document with an object id
      """
      if doc is not None and '_id' in doc:
          doc['id'] = str(doc['_id'])
          del doc['_id']
      return doc
  
new_contents: import logging
  from asyncio_mongo._bson import ObjectId
  from wolverine.module.service import MicroService
  
  logger = logging.getLogger(__name__)
  
  
  class MongoService(MicroService):
  
      def __init__(self, app):
          super(MongoService, self).__init__(app, 'mongo-demo')
          self.version = 2
  
      def read(self, data):
  
          obj_id = data.get('id')
          db_name = data.get('db')
          db = getattr(self.app.mongo, db_name)
          col_name = data.get('collection')
          if db:
              collection = getattr(db, col_name)
              if obj_id and collection:
                  doc = yield from collection.find_one({'_id': ObjectId(obj_id)})
                  logger.debug('doc: ' + str(doc))
                  return fix_id(doc)
          return None
  
  
  def fix_id(doc):
      """
      Replaces the _id value with id
      @:param document: mongo document with an object id
      """
      if doc is not None and '_id' in doc:
          doc['id'] = str(doc['_id'])
          del doc['_id']
      return doc
  
subject: remove None from get calls since it's the default