code: def setUp(self):
      self.stream_ptr = cuda.runtime.streamCreate()
      self.stream = cuda.ExternalStream(self.stream_ptr)
  
imports: import gc
  import threading
  import unittest
  import pytest
  import cupy
  from cupy._creation import from_data
  from cupy import cuda
  from cupy import testing
label_desc: Use image node_id 1 for calling the TestExternalStream obj's underlying member method code with example usage: obj.setUp() without return types