docs: def write_to_textfile(path, registry):
      """Write metrics to the given path.
  
      This is intended for use with the Node exporter textfile collector.
      The path must end in .prom for the textfile collector to process it."""
      tmppath = '%s.%s.%s' % (path, os.getpid(), threading.current_thread().ident)
      with open(tmppath, 'wb') as f:
          f.write(generate_latest(registry))
      # rename(2) is atomic.
      os.rename(tmppath, path)