code: def tearDown(self):
      self._config_user.__exit__(None, None, None)
  
file_path: chainer/tests/chainer_tests/links_tests/loss_tests/test_negative_sampling.py
imports: import unittest
  import numpy
  import chainer
  from chainer import backend
  from chainer.backend import CpuDevice
  from chainer import links
  from chainer import testing
label_desc: Use image node_id 2 for calling the TestNegativeSampling obj's underlying member method code with example usage: obj.tearDown() without return types