code: def testLabelWav(self):
      tmp_dir = self.get_temp_dir()
      wav_data = self._getWavData()
      wav_filename = os.path.join(tmp_dir, "wav_file.wav")
      self._saveTestWavFile(wav_filename, wav_data)
      input_name = "test_input"
      output_name = "test_output"
      graph_filename = os.path.join(tmp_dir, "test_graph.pb")
      with tf.compat.v1.Session() as sess:
          tf.compat.v1.placeholder(tf.string, name=input_name)
          tf.zeros([1, 3], name=output_name)
          with open(graph_filename, "wb") as f:
              f.write(sess.graph.as_graph_def().SerializeToString())
      labels_filename = os.path.join(tmp_dir, "test_labels.txt")
      with open(labels_filename, "w") as f:
          f.write("a\nb\nc\n")
      label_wav.label_wav(
          wav_filename,
          labels_filename,
          graph_filename,
          input_name + ":0",
          output_name + ":0",
          3,
      )
  
file_path: tensorflow-upstream/tensorflow/examples/speech_commands/label_wav_test.py
imports: import os
  import tensorflow
  from tensorflow.examples.speech_commands import label_wav
  from tensorflow.python.platform import test
label_desc: Use image node_id 3 for calling the LabelWavTest obj's underlying member method code with example usage: obj.testLabelWav() without return types