function completeDevice(device) {
  if (!device) {
    return null;
  }

  const existing = this.gladys.stateManager.get('deviceByExternalId', device.external_id);
  if (!existing) {
    return device;
  }
  return { ...existing, ...device };
}
@description Complete device with Gladys exting information.
@param {object} device - Device to check.
@returns {object} Returns completed device.
@example
const device = bluetoothManager.completeDevice({});