code: def setup_class(self):
      self.audio_filename = "test.wav"
      self.spec_dim = 80
      self.hop_len = 100
      self.audio_len = 50000
      self.sample_rate = 10000
      self.spec_len = 1 + (self.audio_len // self.hop_len)
      self.manifest_entry = {"audio_filepath": self.audio_filename}
  
imports: import contextlib
  import tempfile
  from pathlib import Path
  import numpy
  import pytest
  import soundfile
  import torch
  from nemo.collections.tts.parts.preprocessing.features import EnergyFeaturizer, MelSpectrogramFeaturizer, PitchFeaturizer
label_desc: Use image node_id 1 for calling the TestTTSFeatures obj's underlying member method code with example usage: obj.setup_class() without return types