code: def forward_chainerx(self, inputs):
      if len(inputs) == 3:
          x, w, b = inputs
      else:
          (x, w), b = inputs, None
      y = chainerx.conv_transpose(
          x, w, b, self.stride, self.pad, self.outsize
      )
      return (y,)
  
imports: import unittest
  import chainer
  from chainer import functions
  import numpy
  import pytest
  import chainerx
  from chainerx_tests import array_utils
  from chainerx_tests import dtype_utils
  from chainerx_tests import op_utils
label_desc: Use image node_id 3 for calling the _ConvTransposeTestBase obj's underlying member method code with example usage: obj.forward_chainerx(inputs) and returns: y