code: def multi_gpu(gpu_num):
      """Decorator to indicate number of GPUs required to run the test.
  
      Tests can be annotated with this decorator (e.g., ``@multi_gpu(2)``) to
      declare number of GPUs required to run. When running tests, if
      ``CUPY_TEST_GPU_LIMIT`` environment variable is set to value greater
      than or equals to 0, test cases that require GPUs more than the limit will
      be skipped.
      """
  
      check_available("multi_gpu attribute")
      # at this point we know pytest is available for sure
  
      assert 1 < gpu_num
  
      def _wrapper(f):
          return pytest.mark.skipif(
              0 <= _gpu_limit < gpu_num,
              reason="{} GPUs required".format(gpu_num),
          )(pytest.mark.multi_gpu(f))
  
      return _wrapper
  
label_desc: Use image node_id 1 for calling a global function with example usage: multi_gpu(gpu_num) and returns: _wrapper, pytest