new_contents: import argparse
  
  from pysellus import loader, registrar, threader
  
  
  def do_subscribe(s, o):
      s.subscribe(o)
  
  
  if __name__ == '__main__':
      parser = argparse.ArgumentParser()
      parser.add_argument('directory', type=str,
                          metavar='expanded files directory', help='directory of the expanded files')
      args = parser.parse_args()
  
      directory = args.directory
  
      threader.launch_threads(
          threader.build_threads(
              registrar.register(loader.load(directory)), do_subscribe
          )
      )
  
subject: Implement core