code: def forward(self, inputs):
      return (inputs[0] * 2,)
  
imports: import numpy
  import unittest
  import chainer
  from chainer.backends.cuda import to_cpu
  from chainer.function import Function
  from chainer import testing
  from chainer.testing import attr
  from chainercv.links import PickableSequentialChain
  from chainercv.utils.testing import ConstantStubLink
label_desc: Use image node_id 1 for calling the DummyFunc obj's underlying member method code with example usage: obj.forward(inputs) and returns: unknown