code: def forward(self, x):
      self.args.append(x)
      chainer.report({"loss": x.sum()}, self)
  
imports: import unittest
  import numpy
  import chainer
  from chainer import backend
  from chainer.backends import _cpu
  from chainer import dataset
  from chainer import iterators
  from chainer import testing
  from chainer.training import extensions
label_desc: Use image node_id 2 for calling the DummyModel obj's underlying member method code with example usage: obj.forward(x) without return types