function parseExternalId(externalId) {
  const parsedExternalId = externalId.split(':');
  const bridgeSerialNumber = parsedExternalId[1];
  const lightId = parseInt(parsedExternalId[2], 10);
  return {
    bridgeSerialNumber,
    lightId,
  };
}
@description Parse the external id and return the lamp ID.
@param {string} externalId - External id of the device.
@returns {object} Return the lamp ID and bridge serial number.
@example
parseExternalId('philips-hue:1');