code: def enable_notifications(self, enabled=True):
          
          try:
              if enabled:
                  self._object.StartNotify(
                      reply_handler=self._enable_notifications_succeeded,
                      error_handler=self._enable_notifications_failed,
                      dbus_interface='org.bluez.GattCharacteristic1')
              else:
                  self._object.StopNotify(
                      reply_handler=self._enable_notifications_succeeded,
                      error_handler=self._enable_notifications_failed,
                      dbus_interface='org.bluez.GattCharacteristic1')
          except dbus.exceptions.DBusException as e:
              self._enable_notifications_failed(error=e)
docs: Enables or disables value change notifications.
  
          Success or failure will be notified by calls to `characteristic_enable_notifications_succeeded`
          or `enable_notifications_failed` respectively.
  
          Each time when the device notifies a new value, `characteristic_value_updated()` of the related
          device will be called.