Parse the given string, either a Unicode character or ``U+....``,
        and return the corresponding Unicode code point as int.

def _parse_codepoint(self, string):
        """
        Parse the given string, either a Unicode character or ``U+....``,
        and return the corresponding Unicode code point as int.
        """
        if len(string) > 1:
            match = self.CODEPOINT_REGEX.match(string)
            return self._match_to_int(match)
        elif len(string) == 1:
            return self._unichr_to_int(string)
        return -1