code: func (pc *PCCloud) CreateDisk(volumeOptions *VolumeOptions) (pdID string, err error) {
  	photonClient, err := getPhotonClient(pc)
  	if err != nil {
  		klog.Errorf("Photon Cloud Provider: Failed to get photon client for CreateDisk, error: [%v]", err)
  		return "", err
  	}
  
  	diskSpec := photon.DiskCreateSpec{}
  	diskSpec.Name = volumeOptions.Name
  	diskSpec.Flavor = volumeOptions.Flavor
  	diskSpec.CapacityGB = volumeOptions.CapacityGB
  	diskSpec.Kind = DiskSpecKind
  
  	task, err := photonClient.Projects.CreateDisk(pc.projID, &diskSpec)
  	if err != nil {
  		klog.Errorf("Photon Cloud Provider: Failed to CreateDisk. Error[%v]", err)
  		return "", err
  	}
  
  	waitTask, err := photonClient.Tasks.Wait(task.ID)
  	if err != nil {
  		klog.Errorf("Photon Cloud Provider: Failed to wait for task to CreateDisk. Error[%v]", err)
  		return "", err
  	}
  
  	return waitTask.Entity.ID, nil
  }
docs: // Create a volume of given size (in GB).