def METHOD_NAME():
    """
    Do blockpull and check backingchain result , hash value
    """
    if base_index:
        # with --base option scenario
        base_option = " --base %s" % test_obj.snap_path_list[int(base_index)-1]
    else:
        # without --base option scenario
        base_option = " "
    session = vm.wait_for_login()
    expected_hash, check_disk = test_obj.get_hash_value(session,
                                                        "/dev/" + test_obj.new_dev)
    test.log.info("TEST_STEP: Do blockpull")
    virsh.blockpull(vm.name, target_disk, base_option+pull_options,
                    ignore_status=False, debug=True)
    expected_chain = test_obj.convert_expected_chain(expected_chain_index)
    check_obj.check_backingchain_from_vmxml(disk_type, test_obj.new_dev,
                                            expected_chain)
    check_obj.check_hash_list([check_disk], [expected_hash], session)
    session.close()