code: def get_ref_audio(
      self, fname: str, folder: str = "mono"
  ) -> np.ndarray:
      local_ref_path = pathmgr.get_local_path(
          os.path.join(self.ref_audio_dir, folder, f"test_{fname}.wav")
      )
  
      return librosa.load(local_ref_path, sr=None, mono=False)[0]
  
file_path: AugLy/augly/tests/audio_tests/base_unit_test.py
imports: import os
  import tempfile
  import unittest
  from typing import Callable
  import numpy
  from augly.tests import AudioAugConfig
  from augly.utils import pathmgr, TEST_URI
  from augly.utils.libsndfile import install_libsndfile
  import librosa
  import soundfile
label_desc: Use image node_id 5 for calling the BaseAudioUnitTest obj's underlying member method code with example usage: obj.get_ref_audio(fname, folder) and returns: librosa