def check_minProperties(min, instance)
      if instance.is_a?(Mongoff::Record) || instance.is_a?(Hash)
        instance = instance.orm_model.stored_properties_on(instance) if instance.is_a?(Mongoff::Record)
        raise_path_less_error "has too few properties (#{instance.size} for #{min} min)" if instance.size < min
      end