public Reference_devices readReferenceDevices(JsonReader reader) throws IOException {
    Number fridge = null;
    Number hvac = null;
    Number lightning = null;
    Number main = null;
    Number otemp = null;
    
    reader.beginObject();
    while (reader.hasNext()) {
      String key = reader.nextName();
      if (key.equals("fridge")) {
        fridge = reader.nextDouble();
      } else if (key.equals("hvac")) {
        hvac = reader.nextDouble();
      } else if (key.equals("lighting")) {
        lightning = reader.nextDouble();
      } else if (key.equals("main")) {
        main = reader.nextDouble();
      } else if (key.equals("otemp")) {
        otemp = reader.nextDouble();   
      } else {
        System.err.println("Building Info: Unknown key: "+key);
        reader.skipValue();
      }
    }
    reader.endObject();
    return new Reference_devices(fridge, hvac, lightning, main, otemp);
  }