def _next_chunk_id(self):
    existing_chunk_ids = self._chunk_ids()
    next_chunk_id = 0
    if (len(existing_chunk_ids) > 0):
        next_chunk_id = (max([int(i) for i in existing_chunk_ids]) + 1)
    return next_chunk_id
def _next_chunk_id(self):
    existing_chunk_ids = self._chunk_ids()
    next_chunk_id = 0
    if (len(existing_chunk_ids) > 0):
        next_chunk_id = (max([int(i) for i in existing_chunk_ids]) + 1)
    return next_chunk_id