code: def istft(x, n_shift, win_length=None, window="hann", center=True):
      # x: [Time, Channel, Freq]
      if x.ndim == 2:
          single_channel = True
          # x: [Time, Freq] -> [Time, Channel, Freq]
          x = x[:, None, :]
      else:
          single_channel = False
  
      # x: [Time, Channel]
      x = np.stack(
          [
              librosa.istft(
                  x[:, ch].T,  # [Time, Freq] -> [Freq, Time]
                  hop_length=n_shift,
                  win_length=win_length,
                  window=window,
                  center=center,
              )
              for ch in range(x.shape[1])
          ],
          axis=1,
      )
  
      if single_channel:
          # x: [Time, Channel] -> [Time]
          x = x[:, 0]
      return x
  
imports: import librosa
  import numpy
label_desc: Use image node_id 2 for calling a global function with example usage: istft(x, n_shift, win_length, window, center) and returns: x