code: def shutdown_hook(self):
      """default shutdown hook
  
      Typically, shotdown hooks should raise TryNext so all shutdown ops are done
      """
  
      # print "default shutdown hook ok" # dbg
      return
  
imports: import os
  import subprocess
  import warnings
  import sys
  from IPython.core.error import TryNext
  import tempfile
label_desc: Use image node_id 4 for calling a global function with example usage: shutdown_hook() without return types