def METHOD_NAME(tags=None, extension=".txt", time=datetime.now()):
    timestamp = time.strftime("%Y_%m_%d_%H_%M_%S")
    if not tags:
        tags = []
    tags = [str(t) for t in tags if t is not None]
    if len(tags) > 0:
        combined_tags = "_".join(tags)
        filename = timestamp + "_" + combined_tags + extension
    else:
        filename = timestamp + extension
    return filename