':param job: A layer2 job object for archive retrieval object.
:param part_size: The size, in bytes, of the chunks to use when uploading
the archive parts.  The part size must be a megabyte multiplied by
a power of two.'

def __init__(self, job, part_size=DEFAULT_PART_SIZE, num_threads=10):

    super(ConcurrentDownloader, self).__init__(part_size, num_threads)
    self._job = job
