def latency
      start = Time.now.to_f
      send_message!(Protocol::Device::GetTime.new, wait_for: Protocol::Device::StateTime)
      Time.now.to_f - start
    end
def latency
      start = Time.now.to_f
      send_message!(Protocol::Device::GetTime.new, wait_for: Protocol::Device::StateTime)
      Time.now.to_f - start
    end
Pings the device and measures response time.
 @return [Float] Latency from sending a message to receiving a response.