new_contents: from tornado.ioloop import IOLoop
  from tornado.httpclient import AsyncHTTPClient
  from tornado.gen import coroutine
  import time
  
  
  URLS = [
      'http://127.0.0.1:8000',
      'http://127.0.0.1:8000',
      'http://127.0.0.1:8000',
  ]
  
  
  @coroutine
  def get_greetings():
      http_client = AsyncHTTPClient()
      responses = yield [http_client.fetch(url) for url in URLS]
      texts = [resp.body.decode('utf8') for resp in responses]
      return '\n'.join(texts)
  
  
  if __name__ == "__main__":
      loop = IOLoop.instance()
      t1 = time.time()
      text = loop.run_sync(get_greetings)
      print(time.time() - t1, "seconds passed")
      print(text)
  
subject: Add ex4.2: multiple tornado requests