code: def rollback(cls, resource, background=False):
          
          disk_id = cls.usable_id(resource)
          result = cls.call('hosting.disk.rollback_from', disk_id)
  
          if background:
              return result
  
          cls.echo('Disk rollback in progress.')
          cls.display_progress(result)
          return result
docs: Rollback a disk from a snapshot.