code: def callback(self, frame, event, arg):
      if event == "call" or event == "return" or event == "exception":
          self.add_event(event, frame, arg)
  
imports: import gc
  import pprint
  import sys
  import unittest
label_desc: Use image node_id 2 for calling the HookWatcher obj's underlying member method code with example usage: obj.callback(frame, event, arg) without return types