code: def test_argmax_cpu(self):
      self.check_argmax(self.cost, self.xs)
  
imports: import itertools
  import unittest
  import numpy
  import chainer
  from chainer.backends import cuda
  from chainer import functions
  from chainer import gradient_check
  from chainer import testing
  from chainer.testing import attr
label_desc: Use image node_id 10 for calling the TestCRF1d obj's underlying member method code with example usage: obj.test_argmax_cpu() without return types