code: def test_interfaces(self):
      msg = IterationMessage()
      msg.current_iter = 0
      self.assertEqual(msg.current_iter, 0)
      self.assertEqual(msg.ops_to_run, {})
      self.assertEqual(msg.data_feed_dict, {})
      self.assertEqual(msg.current_iter_output, None)
      self.assertEqual(msg.should_stop, None)
      self.assertEqual(msg.phase, TRAIN)
      self.assertEqual(msg.is_training, True)
      self.assertEqual(msg.is_validation, False)
      self.assertEqual(msg.is_inference, False)
      msg.current_iter_output = {"test"}
      self.assertEqual(msg.current_iter_output, {"test"})
      self.assertGreater(msg.iter_duration, 0.0)
      self.assertStartsWith(msg.to_console_string(), "training")
      self.assertEqual(msg.to_tf_summary(0), None)
  
file_path: NiftyNet/tests/run_vars_test.py
imports: from __future__ import absolute_import, print_function
  import numpy
  import tensorflow
  from niftynet.engine.application_iteration import IterationMessage, IterationMessageGenerator
  from niftynet.engine.application_variables import CONSOLE
  from niftynet.engine.signal import TRAIN, ITER_FINISHED, GRAPH_CREATED, SESS_STARTED
  from tests.niftynet_testcase import NiftyNetTestCase
  from tests.application_driver_test import get_initialised_driver
label_desc: Use image node_id 1 for calling the DriverLoopTest obj's underlying member method code with example usage: obj.test_interfaces() without return types