code: def forward_expected(self, inputs):
      (x,) = inputs
      expected_former = numpy.maximum(x, 0)
      expected_latter = numpy.maximum(-x, 0)
      expected = numpy.concatenate(
          (expected_former, expected_latter), axis=self.axis
      )
      assert expected.shape == self.y_shape
      return (expected,)
  
file_path: chainer/tests/chainer_tests/functions_tests/activation_tests/test_crelu.py
imports: import numpy
  from chainer import functions
  from chainer import testing
label_desc: Use image node_id 3 for calling the TestCReLU obj's underlying member method code with example usage: obj.forward_expected(inputs) and returns: expected