docstr: Check the default configuration of the MFCC transform.
docstr_tok: ["Check","the","default","configuration","of","the","MFCC","transform","."]
code: def test_mfcc_defaults(self):
      """Check the default configuration of the MFCC transform."""
      sample_rate = 16000
      audio = common_utils.get_whitenoise(sample_rate=sample_rate)
  
      n_mfcc = 40
      mfcc_transform = torchaudio.transforms.MFCC(
          sample_rate=sample_rate, n_mfcc=n_mfcc, norm="ortho"
      )
      torch_mfcc = mfcc_transform(audio)  # (1, 40, 81)
      self.assertEqual(torch_mfcc.dim(), 3)
      self.assertEqual(torch_mfcc.shape[1], n_mfcc)
      self.assertEqual(torch_mfcc.shape[2], 81)
  
imports: import math
  import torch
  import torchaudio
  import torchaudio.functional
  import torchaudio.transforms
  from torchaudio_unittest import common_utils
label_desc: Use image node_id 7 for calling the Tester obj's underlying member method code with example usage: obj.test_mfcc_defaults() without return types