def get(self, section_name, option_name, do_optionxform=True):
        if do_optionxform:
            # https://docs.python.org/2/library/configparser.html#ConfigParser.RawConfigParser.optionxform
            option_name = self._cp.optionxform(option_name)

        if section_name is None:
            return self._get_optval_in_sections(self.sections(), option_name)
        elif isinstance(section_name, str):
            return self._get_optval_in_sections([section_name], option_name)
        else:
            return self._get_optval_in_sections(section_name, option_name)