_stopInstances = async (projectId, zone, instanceNames) => {
  await Promise.all(
    instanceNames.map(instanceName => {
      return instancesClient
        .stop({
          project: projectId,
          zone: zone,
          instance: instanceName,
        })
        .then(() => {
          console.log(`Instance stopped successfully: ${instanceName}`);
        });
    })
  );
}
@param {Array} instanceNames Names of instance to stop
@return {Promise} Response from stopping instances