docs: def start_scanner(path):
      """
      watch for file events in the supplied path
      """
      try:
          observer = Observer()
          observer.start()
          stream = Stream(file_modified, path, file_events=True)
          observer.schedule(stream)
          print "Watching for changes. Press Ctrl-C to stop."
          while 1:
            pass
      except (KeyboardInterrupt, OSError, IOError):
          observer.unschedule(stream)
          observer.stop()