Add a files filter by regex to this iterator.

        :param regex_expression: regex string to apply.

def add_filter_by_regex(self, regex_expression, filter_type=DefaultFilterType):
        """
        Add a files filter by regex to this iterator.

        :param regex_expression: regex string to apply.
        """
        self.add_filter(FilterRegex(regex_expression), filter_type)
        return self