public String cloneVolume(String volumeName,long capacity,String volumeTypeId,String sourceVolId) throws Exception {
  return createVolume(volumeName,capacity,volumeTypeId,sourceVolId,null);
}

public String cloneVolume ( String volumeName , long capacity , String volumeTypeId , String sourceVolId ) throws Exception { return createVolume ( volumeName , capacity , volumeTypeId , sourceVolId , null ) ; }
clone volume operation ( it is asynchronous operation )
