code: def test_istft_multi(y_multi):
      # Verify that a stereo ISTFT matches on each channel
      y, sr = y_multi
  
      # Assume the forward transform works properly in stereo
      D = librosa.stft(y)
  
      # Invert per channel
      y0m = librosa.istft(D[0])
      y1m = librosa.istft(D[1])
  
      # Invert both channels at once
      ys = librosa.istft(D)
  
      # Check each channel
      assert np.allclose(y0m, ys[0])
      assert np.allclose(y1m, ys[1])
  
      # Check that they're not both the same
      assert not np.allclose(ys[0], ys[1])
  
imports: import os
  import librosa
  import glob
  import numpy
  import scipy.io
  import scipy.stats
  import pytest
  import warnings
  from unittest import mock
  from typing import List, Union
  from contextlib import nullcontext
  from test_core import srand
label_desc: Use image node_id 11 for calling a global function with example usage: test_istft_multi(y_multi) without return types