docs: def read_config_file(self, file_name):
          """
          Reads a CWR grammar config file.
  
          :param file_name: name of the text file
          :return: the file's contents
          """
          with open(os.path.join(self.__path(), os.path.basename(file_name)),
                    'rt') as file_config:
              return self._parser.parseString(file_config.read())