code: def test_call_gpu(self):
      self._test_call(gpu=0)
  
file_path: chainerrl/tests/links_tests/test_mlp_bn.py
imports: import unittest
  import chainer
  import chainer.functions
  from chainer import testing
  from chainer.testing import attr
  import numpy
  import chainerrl
label_desc: Use image node_id 3 for calling the TestMLPBN obj's underlying member method code with example usage: obj.test_call_gpu() without return types