Parse pubnote and populate correct fields.

def set_pubnote(self, pubnote):
        """Parse pubnote and populate correct fields."""
        if 'publication_info' in self.obj.get('reference', {}):
            self.add_misc(u'Additional pubnote: {}'.format(pubnote))
            return

        if self.RE_VALID_PUBNOTE.match(pubnote):
            pubnote = split_pubnote(pubnote)
            pubnote = convert_old_publication_info_to_new([pubnote])[0]
            self._ensure_reference_field('publication_info', pubnote)
        else:
            self.add_misc(pubnote)