code: def test_load_audio(self):
      wav, sr = load_audio(WAV_FILE)
      self.assertEqual(wav.shape, (1, 41885))
      self.assertEqual(sr, 22050)
  
      spec = wav_to_spec(
          wav, n_fft=1024, hop_length=512, win_length=1024, center=False
      )
      mel = wav_to_mel(
          wav,
          n_fft=1024,
          num_mels=80,
          sample_rate=sr,
          hop_length=512,
          win_length=1024,
          fmin=0,
          fmax=8000,
          center=False,
      )
      mel2 = spec_to_mel(
          spec,
          n_fft=1024,
          num_mels=80,
          sample_rate=sr,
          fmin=0,
          fmax=8000,
      )
  
      self.assertEqual((mel - mel2).abs().max(), 0)
      self.assertEqual(spec.shape[0], mel.shape[0])
      self.assertEqual(spec.shape[2], mel.shape[2])
  
      spec_db = amp_to_db(spec)
      spec_amp = db_to_amp(spec_db)
  
      self.assertAlmostEqual(
          (spec - spec_amp).abs().max(), 0, delta=1e-4
      )
  
imports: import copy
  import os
  import unittest
  import torch
  from trainer.logging.tensorboard_logger import TensorboardLogger
  from tests import assertHasAttr, assertHasNotAttr, get_tests_data_path, get_tests_input_path, get_tests_output_path
  from TTS.config import load_config
  from TTS.encoder.utils.generic_utils import setup_encoder_model
  from TTS.tts.configs.vits_config import VitsConfig
  from TTS.tts.models.vits import Vits, VitsArgs, VitsAudioConfig, amp_to_db, db_to_amp, load_audio, spec_to_mel, wav_to_mel, wav_to_spec
  from TTS.tts.utils.speakers import SpeakerManager
label_desc: Use image node_id 1 for calling the TestVits obj's underlying member method code with example usage: obj.test_load_audio() without return types