def regex(self, *pattern, **kwargs):
        """
        Add re pattern

        :param pattern:
        :type pattern:
        :param kwargs:
        :type kwargs:
        :return:
        :rtype:
        """
        set_defaults(self._kwargs, kwargs)
        set_defaults(self._regex_defaults, kwargs)
        set_defaults(self._defaults, kwargs)
        pattern = self.rebulk.build_re(*pattern, **kwargs)
        part = ChainPart(self, pattern)
        self.parts.append(part)
        return part
Add re pattern

        :param pattern:
        :type pattern:
        :param kwargs:
        :type kwargs:
        :return:
        :rtype: