code: def test_musan_metadata(self, subset):
      dataset = Musan(self.get_base_temp_dir(), subset)
      for idx in range(len(dataset)):
          file_path, sample_rate, file_name = dataset.get_metadata(idx)
          self.assertTrue(file_name in self.samples[subset])
          self.assertEqual(
              file_path, self.samples[subset][file_name][1]
          )
          self.assertEqual(sample_rate, _SAMPLE_RATE)
  
file_path: audio/test/torchaudio_unittest/prototype/datasets/musan_test.py
imports: import os
  from collections import defaultdict
  from parameterized import parameterized
  from torchaudio.prototype.datasets import Musan
  from torchaudio_unittest.common_utils import get_whitenoise, save_wav, TempDirMixin, TorchaudioTestCase
label_desc: Use image node_id 3 for calling the MusanTest obj's underlying member method code with example usage: obj.test_musan_metadata(subset) without return types