code: def handle_signals(sig, frame):
      signal_blackboard[sig]["tripped"] += 1
      signal_blackboard[sig]["tripped_by"] = thread.get_ident()
  
imports: import unittest
  import signal
  import os
  import sys
  from test.support import threading_helper
  import _thread
  import time
label_desc: Use image node_id 2 for calling a global function with example usage: handle_signals(sig, frame) without return types