code: func GetSupportedVolumeFromPVSpec(spec *core_v1.PersistentVolumeSpec) string {
  	if spec.HostPath != nil {
  		return "hostPath"
  	}
  	if spec.AWSElasticBlockStore != nil {
  		return "aws_ebs"
  	}
  	if spec.GCEPersistentDisk != nil {
  		return "gce-pd"
  	}
  	if spec.Cinder != nil {
  		return "cinder"
  	}
  	if spec.Glusterfs != nil {
  		return "glusterfs"
  	}
  	return ""
  }
docs: // GetSupportedVolumeFromPVSpec gets supported volume from PV spec