code: def test_find_audio_files_multiple_dirs(self):
      file_paths = find_audio_files_in_paths(
          [
              os.path.join(DEMO_DIR, "short_noises"),
              os.path.join(DEMO_DIR, "ir"),
          ]
      )
      assert len(file_paths) == 7
      assert (
          file_paths[0].name
          == "130921_iPhone_rub_channel0_chunk83_aug2.wav"
      )
      assert file_paths[-1].name == "rir48000.wav"
  
file_path: audiomentations/tests/test_utils.py
imports: import os
  import numpy
  import pytest
  from audiomentations.core.utils import calculate_desired_noise_rms, convert_decibels_to_amplitude_ratio, find_audio_files_in_paths, calculate_rms, calculate_rms_without_silence
  from demo.demo import DEMO_DIR
label_desc: Use image node_id 6 for calling the TestUtils obj's underlying member method code with example usage: obj.test_find_audio_files_multiple_dirs() without return types