code: def forward_chainer(self, inputs):
      (x,) = inputs
      y = chainer.functions.max_pooling_nd(
          x,
          ksize=self.ksize,
          stride=self.stride,
          pad=self.pad,
          cover_all=self.cover_all,
      )
      # Convert -inf to finite numbers.
      y = chainer.functions.maximum(y, numpy.full_like(y.array, -1e4))
      return (y,)
  
imports: import functools
  from operator import mul
  import unittest
  import chainer
  import numpy
  import pytest
  import chainerx
  from chainerx_tests import op_utils
label_desc: Use image node_id 4 for calling the TestMaxPool obj's underlying member method code with example usage: obj.forward_chainer(inputs) and returns: y