code: def test_str(self):
      trigger = training.triggers.IntervalTrigger(*self.interval)
  
      expected = "IntervalTrigger({}, '{}')".format(*self.interval)
      actual = str(trigger)
  
      assert expected == actual, 'Expected "{}" == "{}"'.format(
          expected, actual
      )
  
file_path: chainer/tests/chainer_tests/training_tests/triggers_tests/test_interval_trigger.py
imports: from __future__ import division
  import random
  import tempfile
  import unittest
  import numpy
  from chainer import serializers
  from chainer import testing
  from chainer.testing import condition
  from chainer import training
label_desc: Use image node_id 6 for calling the TestIntervalTrigger obj's underlying member method code with example usage: obj.test_str() without return types