code: def forward_expected(self, inputs):
      (x,) = inputs
      y_expected = numpy.pad(x, self.pad_width, self.mode)
      return (y_expected.astype(self.dtype),)
  
file_path: chainer/tests/chainer_tests/functions_tests/array_tests/test_pad.py
imports: import numpy
  from chainer import functions
  from chainer import testing
label_desc: Use image node_id 4 for calling the TestPadDefault obj's underlying member method code with example usage: obj.forward_expected(inputs) and returns: y_expected