code: def logger_file(self, value):
          
          self.__logger_file = value
          if self.__logger_file:
              # If set logging file,
              # then add file handler and remove stream handler.
              self.logger_file_handler = logging.FileHandler(self.__logger_file)
              self.logger_file_handler.setFormatter(self.logger_formatter)
              for _, logger in six.iteritems(self.logger):
                  logger.addHandler(self.logger_file_handler)
docs: The logger file.
  
          If the logger_file is None, then add stream handler and remove file
          handler. Otherwise, add file handler and remove stream handler.
  
          :param value: The logger_file path.
          :type: str