// This seems way too complicated
  public void registerNotify(
      UUID serviceUUID, UUID characteristicUUID, Callback success, Callback fail) {

    Log.d(LOG_TAG, "registerNotify");

    if (gatt == null) {
      fail.invoke("BluetoothGatt is null");
      return;
    }

    BluetoothGattService service = gatt.getService(serviceUUID);
    BluetoothGattCharacteristic characteristic =
        findNotifyCharacteristic(service, characteristicUUID);
    // String key = generateHashKey(serviceUUID, characteristic);

    if (characteristic != null) {
      Log.d(LOG_TAG, "characteristic ok");

      if (gatt.setCharacteristicNotification(characteristic, true)) {

        BluetoothGattDescriptor descriptor =
            characteristic.getDescriptor(UUID.fromString(CHARACTERISTIC_NOTIFICATION_CONFIG));
        if (descriptor != null) {
          Log.d(LOG_TAG, "trovato descriptor");

          // prefer notify over indicate
          if ((characteristic.getProperties() & BluetoothGattCharacteristic.PROPERTY_NOTIFY) != 0) {
            Log.d(LOG_TAG, "Characteristic " + characteristicUUID + " set NOTIFY");
            descriptor.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);
          } else if ((characteristic.getProperties()
                  & BluetoothGattCharacteristic.PROPERTY_INDICATE)
              != 0) {
            Log.d(LOG_TAG, "Characteristic " + characteristicUUID + " set INDICATE");
            descriptor.setValue(BluetoothGattDescriptor.ENABLE_INDICATION_VALUE);
          } else {
            Log.d(
                LOG_TAG,
                "Characteristic "
                    + characteristicUUID
                    + " does not have NOTIFY or INDICATE property set");
          }

          if (gatt.writeDescriptor(descriptor)) {
            // Tutto ok
            Log.d(LOG_TAG, "registerNotify completato");
            success.invoke();
          } else {
            fail.invoke(
                "Failed to set client characteristic notification for " + characteristicUUID);
          }

        } else {
          fail.invoke("Set notification failed for " + characteristicUUID);
        }

      } else {
        fail.invoke("Failed to register notification for " + characteristicUUID);
      }

    } else {
      fail.invoke("Characteristic " + characteristicUUID + " not found");
    }
  }