code: def test_evaluator(self):
      reporter = chainer.Reporter()
      reporter.add_observer("target", self.target)
      with reporter:
          self.evaluator.evaluate()
  
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 TestEvaluatorProgressBar obj's underlying member method code with example usage: obj.test_evaluator() without return types