code: def forward(self, inputs, device):
      (h,) = inputs
      loss = functions.decov(h, self.reduce)
      return (loss,)
  
imports: import unittest
  import numpy
  import six
  import chainer
  from chainer.backends import cuda
  from chainer import functions
  from chainer import testing
  from chainer.testing import attr
  from chainer.testing import backend
label_desc: Use image node_id 4 for calling the TestDeCov obj's underlying member method code with example usage: obj.forward(inputs, device) and returns: loss