docs: def simple_in_memory_settings(cls):
      """
      Decorator that returns a class that "persists" data in-memory.  Mostly
       useful for testing
      :param cls: the class whose features should be persisted in-memory
      :return: A new class that will persist features in memory
      """
  
      class Settings(ff.PersistenceSettings):
          id_provider = ff.UuidProvider()
          key_builder = ff.StringDelimitedKeyBuilder()
          database = ff.InMemoryDatabase(key_builder=key_builder)
  
      class Model(cls, Settings):
          pass
  
      Model.__name__ = cls.__name__
      Model.__module__ = cls.__module__
      return Model