docs: def init_logging(stream=sys.stderr, filepath=None,
                   format='%(asctime).19s [%(levelname)s] %(name)s: %(message)s'):
      """
      Setup logging for the microcache module, but only do it once!
  
      :param stream: stream to log to (defaults to sys.stderr)
      :param filepath: path to a file to log to as well (defaults to None)
      :param format: override the default format with whatever you like
      """
      if not (len(logger.handlers) == 1 and isinstance(logger.handlers[0], logging.NullHandler)):
          logger.warn('logging has already been initialized, refusing to do it again')
          return
      formatter = logging.Formatter(format)
      if stream is not None:
          handler = logging.StreamHandler(stream=stream)
          handler.setFormatter(formatter)
          logger.addHandler(handler)
      if filepath is not None:
          handler = logging.FileHandler(filename=filepath)
          handler.setFormatter(formatter)
          logger.addHandler(handler)
      logger.info('successfully initialized logger')