code: def set_fftlib(lib: Optional[ModuleType] = None) -> None:
      """Set the FFT library used by librosa.
  
      Parameters
      ----------
      lib : None or module
          Must implement an interface compatible with `numpy.fft`.
          If ``None``, reverts to `numpy.fft`.
  
      Examples
      --------
      Use `pyfftw`:
  
      >>> import pyfftw
      >>> librosa.set_fftlib(pyfftw.interfaces.numpy_fft)
  
      Reset to default `numpy` implementation
  
      >>> librosa.set_fftlib()
      """
      global __FFTLIB
      if lib is None:
          from numpy import fft
  
          lib = fft
  
      __FFTLIB = lib
  
imports: from types import ModuleType
  from typing import Optional
label_desc: Use image node_id 1 for calling a global function with example usage: set_fftlib(lib) without return types