':type api: :class:`boto.glacier.layer1.Layer1`
:param api: A layer1 glacier object.
:type vault_name: str
:param vault_name: The name of the vault.
:type part_size: int
: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.
:type num_threads: int
:param num_threads: The number of threads to spawn for the thread pool.
The number of threads will control how much parts are being
concurrently uploaded.'

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

    super(ConcurrentUploader, self).__init__(part_size, num_threads)
    self._api = api
    self._vault_name = vault_name
