class MQTT::Homie::Device

def init
  return yield state if state == :init
  prior_state = state
  mqtt.publish("#{topic}/$state", (self.state = :init).to_s, retain: true, qos: 1)
  result = nil
  mqtt.batch_publish do
    result = yield prior_state
  end
  mqtt.publish("#{topic}/$state", (self.state = :ready).to_s, retain: true, qos: 1)
  result
end