code: def parcor_stable(filt):
    
    try:
      return all(abs(k) < 1 for k in parcor(ZFilter(filt.denpoly)))
    except ParCorError:
      return False
docs: Tests whether the given filter is stable or not by using the partial
    correlation coefficients (reflection coefficients) of the given filter.
  
    Parameters
    ----------
    filt :
      A LTI filter as a LinearFilter object.
  
    Returns
    -------
    A boolean that is true only when all correlation coefficients are inside the
    unit circle. Critical stability (i.e., when outer coefficient has magnitude
    equals to one) is seem as an instability, and returns False.
  
    See Also
    --------
    parcor :
      Partial correlation coefficients generator.
    lsf_stable :
      Tests filter stability with Line Spectral Frequencies (LSF) values.