def set_created_at
      self.created_at ||= DateTime.now.in_time_zone(Time.zone) if Dynamoid::Config.timestamps
    end
def set_created_at
      self.created_at ||= DateTime.now.in_time_zone(Time.zone) if Dynamoid::Config.timestamps
    end
Automatically called during the created callback to set the created_at time.

 @since 0.2.0