code: def tau_from_final_mass_spin(final_mass, final_spin, l=2, m=2, nmodes=1):
      
      return get_lm_f0tau(final_mass, final_spin, l, m, nmodes)[1]
docs: Returns QNM damping time for the given mass and spin and mode.
  
      Parameters
      ----------
      final_mass : float or array
          Mass of the black hole (in solar masses).
      final_spin : float or array
          Dimensionless spin of the final black hole.
      l : int or array, optional
          l-index of the harmonic. Default is 2.
      m : int or array, optional
          m-index of the harmonic. Default is 2.
      nmodes : int, optional
          The number of overtones to generate. Default is 1.
  
      Returns
      -------
      float or array
          The damping time of the QNM(s), in seconds. If only a single mode is
          requested (and mass, spin, l, and m are not arrays), this will be a
          float. If multiple modes requested, will be an array with shape
          ``[input shape x] nmodes``, where ``input shape`` is the broadcasted
          shape of the inputs.