old_contents: from pymemcache.client.hash import HashClient
  
  
  class Client(HashClient):
      def get_many(self, keys, gets=False, *args, **kwargs):
          # pymemcache's HashClient may returns {'key': False}
          end = super(Client, self).get_many(keys, gets, args, kwargs)
  
          return {key: end[key] for key in end if end[key]}
  
      get_multi = get_many
  
new_contents: from pymemcache.client.hash import HashClient
  
  
  class Client(HashClient):
      def get_many(self, keys, gets=False, *args, **kwargs):
          # pymemcache's HashClient may returns {'key': False}
          end = super(Client, self).get_many(keys, gets, args, kwargs)
  
          return {key: end.get(key) for key in end if end.get(key)}
  
      get_multi = get_many
  
subject: Fix get value more safe