code: def test_encode(self):
      if MFCCEncoder is None:
          print(
              "Skipping this test since MFCCEncoder cannot be imported"
          )
          return
  
      dir_path = os.path.dirname(os.path.realpath(__file__))
      audio_paths = [
          os.path.join(dir_path, "test_audio_1.wav"),
          os.path.join(dir_path, "test_audio_2.wav"),
          None,
      ]
  
      encoder = MFCCEncoder()
      encoder.prepare(audio_paths)
      encoded_audio = encoder.encode(audio_paths)
  
      self.assertTrue(isinstance(encoded_audio, Tensor))
      # We expect the first dimension to equal the number of images
      self.assertEqual(encoded_audio.size(0), 3)
      self.assertEqual(encoded_audio.size(1), 2000)
  
imports: import os
  import unittest
  from torch import Tensor
  from lightwood.encoder.audio import MFCCEncoder
label_desc: Use image node_id 1 for calling the TestMFCCEncoder obj's underlying member method code with example usage: obj.test_encode() without return types