@staticmethod
def transform_args_to_list(items):
    """Transform second part of each item in items in a list if it's not
        one.

        :argument items: List of items to transform
        :type items: iterable of 2-tuple

        :returns: Transformed list
        :rtype: iterable of 2-tuple : [(bool, list)]

        >>> list(ArgumentsParser.transform_args_to_list([
        ...   (None, '<arg1>'),
        ...   (None, ['<arg2>', '<arg3>'])
        ... ]))
        ... # doctest: +NORMALIZE_WHITESPACE
        [(None, ['<arg1>']),
         (None, ['<arg2>', '<arg3>'])]

        """
    for required, args in items:
        if not isinstance(args, list):
            args = [args]
        yield required, args
