class MQTT::Homie::Node

def unpublish
  return unless published?
  @published = false
  mqtt.publish("#{topic}/$name", retain: true, qos: 0)
  mqtt.publish("#{topic}/$type", retain: true, qos: 0)
  mqtt.publish("#{topic}/$properties", retain: true, qos: 0)
  @properties.each_value(&:unpublish)
end