code: def check_forward(self, x):
      with mock.patch("cupy.cuda.nvtx.RangePush") as push, mock.patch(
          "cupy.cuda.nvtx.RangePop"
      ) as pop:
          with self.h:
              chainer.Variable(x) + chainer.Variable(x)
  
      push.assert_called_once_with("_ + _.forward")
      pop.assert_called_once_with()
  
imports: import unittest
  import mock
  import numpy
  import chainer
  from chainer.backends import cuda
  from chainer import function_hooks
  from chainer import testing
  from chainer.testing import attr
label_desc: Use image node_id 3 for calling the TestCUDAProfileHook obj's underlying member method code with example usage: obj.check_forward(x) without return types