code: def test_trigger_sparse_call(self):
      trainer = testing.get_trainer_with_mock_updater(
          stop_trigger=None, iter_per_epoch=self.iter_per_epoch
      )
      trigger = training.triggers.ManualScheduleTrigger(*self.schedule)
      accumulated = False
      for expected, finished in zip(self.expected, self.finished):
          trainer.updater.update()
          accumulated = accumulated or expected
          if random.randrange(2):
              self.assertEqual(trigger(trainer), accumulated)
              self.assertEqual(trigger.finished, finished)
              accumulated = False
  
imports: from __future__ import division
  import random
  import tempfile
  import unittest
  import numpy
  import six
  from chainer import serializers
  from chainer import testing
  from chainer.testing import condition
  from chainer import training
label_desc: Use image node_id 3 for calling the TestManualScheduleTrigger obj's underlying member method code with example usage: obj.test_trigger_sparse_call() without return types