Set a temporary sys.version_info tuple

    :param version_tuple: a fake sys.version_info tuple

def sys_version(version_tuple):
    """
    Set a temporary sys.version_info tuple

    :param version_tuple: a fake sys.version_info tuple
    """

    old_version = sys.version_info
    sys.version_info = version_tuple
    yield
    sys.version_info = old_version