code: def test_grabgpus():
      pop_if_set()
      res = grab_gpus(0)
      assert os.environ["CUDA_VISIBLE_DEVICES"] == ""
      assert res == 0
  
file_path: py3nvml/tests/test_py3nvml.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import numpy
  from time import sleep
  from py3nvml.py3nvml import *
  import pytest
  from py3nvml.utils import grab_gpus, get_free_gpus
  import os
label_desc: Use image node_id 3 for calling a global function with example usage: test_grabgpus() without return types