code: def test_stop(self):
      def _sleep():
          lp.wait_for_stop()
  
      def _stop():
          lp.stop()
  
      program = lp.Program("stop")
      program.add_node(
          lp.MultiThreadingColocation(
              [lp.PyNode(_sleep), lp.PyNode(_stop)]
          ),
          label="node",
      )
      waiter = lp.launch(program, launch_type="test_mt", test_case=self)
      waiter.wait()
  
file_path: launchpad/launchpad/nodes/multi_threading_colocation/node_test.py
imports: import threading
  from absl.testing import absltest
  import courier
  import launchpad
  from launchpad.launch import worker_manager
label_desc: Use image node_id 6 for calling the NodeTest obj's underlying member method code with example usage: obj.test_stop() without return types