def METHOD_NAME(factors, **args):
    """Sort low-level factors in increasing 'complexity' order."""
    def order_if_multiple_key(factor):
        f, n = factor
        return len(f), n, default_sort_key(f)
    def order_no_multiple_key(f):
        return len(f), default_sort_key(f)
    if args.get('multiple', True):
        return sorted(factors, key=order_if_multiple_key)
    return sorted(factors, key=order_no_multiple_key)