code: def test_ctxGetCurrent_thread(self):
      # Make sure to create context in main thread.
      cupy.arange(1)
  
      def f(self):
          self._result0 = driver.ctxGetCurrent()
          cupy.cuda.Device().use()
          cupy.arange(1)
          self._result1 = driver.ctxGetCurrent()
  
      self._result0 = None
      self._result1 = None
      t = threading.Thread(target=f, args=(self,))
      t.daemon = True
      t.start()
      t.join()
  
      # The returned context pointer must be NULL on sub thread
      # without valid context.
      assert 0 == self._result0
  
      # After the context is created, it should return the valid
      # context pointer.
      assert 0 != self._result1
  
file_path: cupy/tests/cupy_tests/cuda_tests/test_driver.py
imports: import pickle
  import threading
  import unittest
  import cupy
  from cupy import testing
  from cupy.cuda import driver
label_desc: Use image node_id 2 for calling the TestDriver obj's underlying member method code with example usage: obj.test_ctxGetCurrent_thread() without return types