code: def test_audio_dataset_from_directory_standalone(self):
      # Test retrieving audio samples withouts labels from a directory and its
      # subdirs.
      # Save a few extra audio in the parent directory.
      directory = self._prepare_directory(count=7, num_classes=2)
      for i, audio in enumerate(self._get_audio_samples(3)):
          filename = f"audio_{i}.wav"
          with open(os.path.join(directory, filename), "wb") as f:
              f.write(audio.numpy())
  
      dataset = audio_dataset_utils.audio_dataset_from_directory(
          directory,
          batch_size=5,
          output_sequence_length=30,
          labels=None,
      )
      batch = next(iter(dataset))
      # We return plain audio
      self.assertEqual(batch.shape, (5, 30, 1))
      self.assertEqual(batch.dtype.name, "float32")
      # Count samples
      batch_count = 0
      sample_count = 0
      for batch in dataset:
          batch_count += 1
          sample_count += batch.shape[0]
      self.assertEqual(batch_count, 2)
      self.assertEqual(sample_count, 10)
  
imports: import os
  import numpy
  from keras import testing
  from keras.utils import audio_dataset_utils
  from keras.utils.module_utils import tensorflow
label_desc: Use image node_id 3 for calling the AudioDatasetFromDirectoryTest obj's underlying member method code with example usage: obj.test_audio_dataset_from_directory_standalone() without return types