create a volume then clone the contents of
        the backup into the new volume

def clone(self, source_id, backup_id, size,
              volume_id=None, source_host=None):
        """
        create a volume then clone the contents of
        the backup into the new volume
        """
        volume_id = volume_id or str(uuid.uuid4())
        return self.http_put('/volumes/%s' % volume_id,
                             params=self.unused({
                                 'source_host': source_host,
                                 'source_volume_id': source_id,
                                 'backup_id': backup_id,
                                 'size': size
                             }))