def register_regex_entity(self, regex_str):
        """
        A regular expression making use of python named group expressions.

        Example: (?P<Artist>.*)

        regex_str(str): a string representing a regular expression as defined above
        """
        if regex_str and regex_str not in self._regex_strings:
            self._regex_strings.add(regex_str)
            self.regular_expressions_entities.append(re.compile(regex_str, re.IGNORECASE))
A regular expression making use of python named group expressions.

        Example: (?P<Artist>.*)

        regex_str(str): a string representing a regular expression as defined above