docs: def configure_logging(level=logging.DEBUG):
      '''Configures the root logger for command line applications.
  
      A stream handler will be added to the logger that directs
      messages to the standard error stream.
  
      By default, *no* messages will be filtered out: set a higher
      level on derived/child loggers to achieve filtering.
  
      Warning
      -------
      Logging should only be configured once at the main entry point of the
      application!
      '''
      fmt = '%(asctime)s | %(levelname)-8s | %(name)-40s | %(message)s'
      datefmt = '%Y-%m-%d %H:%M:%S'
      formatter = logging.Formatter(fmt=fmt, datefmt=datefmt)
  
      logger = logging.getLogger()  # returns the root logger
  
      stderr_handler = logging.StreamHandler(stream=sys.stderr)
      stderr_handler.name = 'err'
      stderr_handler.setLevel(level)
      stderr_handler.setFormatter(formatter)
      logger.addHandler(stderr_handler)