code: def test_singular_gpu(self):
      x = chainer.Variable(
          cuda.to_gpu(numpy.zeros((1, 2, 2), dtype=numpy.float32))
      )
  
      # Should raise exception only when debug mode.
      with chainer.using_config("debug", False):
          functions.batch_inv(x)
  
      with chainer.using_config("debug", True):
          with self.assertRaises(ValueError):
              functions.batch_inv(x)
  
imports: import unittest
  import numpy
  import chainer
  from chainer.backends import cuda
  from chainer import functions
  from chainer import testing
  from chainer.testing import attr
  from chainer.utils import type_check
label_desc: Use image node_id 4 for calling the BatchInvFunctionRaiseTest obj's underlying member method code with example usage: obj.test_singular_gpu() without return types