code: def assertLoaderYields(self, values):
      self.assertEqual(list(self._loader.Load()), values)
  
imports: import functools
  import glob
  import os
  import shutil
  from unittest import mock
  import tensorflow
  from tensorboard.backend.event_processing import directory_loader
  from tensorboard.backend.event_processing import directory_watcher
  from tensorboard.backend.event_processing import event_file_loader
  from tensorboard.backend.event_processing import io_wrapper
  from tensorboard.util import test_util
label_desc: Use image node_id 3 for calling the DirectoryLoaderTest obj's underlying member method code with example usage: obj.assertLoaderYields(values) without return types