def download(name):
    if not update_available(name):
        raise SaltInvocationError('Update not available: {0}'.format(name))

    if name in list_downloads():
        return True

    cmd = ['softwareupdate', '--download', name]
    salt.utils.mac_utils.execute_return_success(cmd)

    return name in list_downloads()
Download a named update so that it can be installed later with the
dataset/ETHPy150Open saltstack/salt/salt/modules/mac_softwareupdate.py/download