def format_string_argument(argument):
    """
    Fire takes multiple arguments (comma separated) as list or tuple.
    Check argument type and put it to string.

    :type  argument: tuple or list
    :param argument: The argument passed.

    :rtype:   string
    :return:  Separated comma strings convertion for lists and tuples.
    """
    if argument is None:
        return None
    elif isinstance(argument, (list, tuple)):
        return ','.join(argument)
    return argument
