code: def _check_forward(self, x):
      y = self.link(x)
  
      self.assertIsInstance(y, chainer.Variable)
      self.assertIsInstance(y.array, type(x))
      self.assertEqual(y.shape, x.shape)
      self.assertEqual(y.dtype, x.dtype)
  
      x = chainer.backends.cuda.to_cpu(x)
      y = chainer.backends.cuda.to_cpu(y.array)
      scale = chainer.backends.cuda.to_cpu(self.link.scale.array)
  
      norm = np.linalg.norm(x, axis=1, keepdims=True) + self.eps
      expect = x / norm * scale[:, np.newaxis, np.newaxis]
      np.testing.assert_almost_equal(y, expect)
  
file_path: chainercv/tests/links_tests/model_tests/ssd_tests/test_normalize.py
imports: import numpy
  import unittest
  import chainer
  from chainer import initializers
  from chainer import testing
  from chainer.testing import attr
  from chainercv.links.model.ssd import Normalize
label_desc: Use image node_id 2 for calling the TestNormalize obj's underlying member method code with example usage: obj._check_forward(x) without return types