code: def __str__(self):
      tips = "Can't connect to Hub Server: {}".format(self.url)
      return tips
  
file_path: PaddleHub/paddlehub/server/server_source.py
imports: import json
  from typing import List
  import requests
  import paddlehub
  from paddlehub.utils import platform
  from paddlehub.utils.utils import convert_version
  from paddlehub.utils.utils import Version
label_desc: Use image node_id 2 for calling the ServerConnectionError obj's underlying member method code with example usage: obj.__str__() and returns: tips