code: def forward(self, link, inputs, backend_config):
      (x,) = inputs
      with chainer.using_config("train", not self.test):
          y = link(x)
      return (y,)
  
imports: import contextlib
  import os
  import tempfile
  import unittest
  import numpy
  import chainer
  from chainer import links
  from chainer import testing
label_desc: Use image node_id 6 for calling the DecorrelatedBatchNormalizationTest obj's underlying member method code with example usage: obj.forward(link, inputs, backend_config) and returns: y