code: def check_forward(self, dst_device_spec, src_device_spec, dst_device):
      self._check_forward_internal(
          dst_device_spec, src_device_spec, dst_device, "array"
      )
      self._check_forward_internal(
          dst_device_spec,
          src_device_spec,
          dst_device,
          "non_requires_grad",
      )
      self._check_forward_internal(
          dst_device_spec, src_device_spec, dst_device, "requires_grad"
      )
  
imports: import unittest
  import numpy
  import pytest
  import chainer
  from chainer import backend
  from chainer.backends import _cpu
  from chainer.backends import cuda
  from chainer import functions
  from chainer import testing
  import chainerx
label_desc: Use image node_id 3 for calling the CopyTestBase obj's underlying member method code with example usage: obj.check_forward(dst_device_spec, src_device_spec, dst_device) without return types