code: def check_forward(self, x, offset, W, b, stride, pad):
      with chainer.using_config("use_cudnn", self.use_cudnn):
          _, _, h, w = x.shape
          _, _, kh, kw = W.shape
          offset[:, : kh * kw] = -1 * stride[1]
          offset[:, kh * kw :] = 1 * stride[0]
  
          x = chainer.Variable(x)
          offset = chainer.Variable(offset)
          out = deformable_convolution_2d_sampler(
              x, offset, W, b, stride, pad
          ).data
          pad = (pad[0] + 1 * stride[0], pad[1] + 1 * stride[1])
          expeceted = convolution_2d(x, W, b, stride, pad).data
          expeceted = expeceted[:, :, 2:, :-2]
      testing.assert_allclose(out, expeceted)
  
imports: import unittest
  import numpy
  import chainer
  from chainer import cuda
  from chainer.functions import convolution_2d
  from chainer.functions import deformable_convolution_2d_sampler
  from chainer import utils
  from chainer import testing
  from chainer.testing import attr
label_desc: Use image node_id 2 for calling the TestDeformableConvolution2DSamplerFunctionLeftBottomOffset obj's underlying member method code with example usage: obj.check_forward(x, offset, W, b, stride, pad) without return types