code: def final_mass_from_initial(mass1, mass2, spin1x=0., spin1y=0., spin1z=0.,
                              spin2x=0., spin2y=0., spin2z=0.,
                              approximant='SEOBNRv4'):
      
      return get_final_from_initial(mass1, mass2, spin1x, spin1y, spin1z,
                                    spin2x, spin2y, spin2z, approximant)[0]
docs: Estimates the final mass from the given initial parameters.
  
      This uses the fits used by the EOBNR models for converting from initial
      parameters to final. Which version used can be controlled by the
      ``approximant`` argument.
  
      Parameters
      ----------
      mass1 : float
          The mass of one of the components, in solar masses.
      mass2 : float
          The mass of the other component, in solar masses.
      spin1x : float, optional
          The dimensionless x-component of the spin of mass1. Default is 0.
      spin1y : float, optional
          The dimensionless y-component of the spin of mass1. Default is 0.
      spin1z : float, optional
          The dimensionless z-component of the spin of mass1. Default is 0.
      spin2x : float, optional
          The dimensionless x-component of the spin of mass2. Default is 0.
      spin2y : float, optional
          The dimensionless y-component of the spin of mass2. Default is 0.
      spin2z : float, optional
          The dimensionless z-component of the spin of mass2. Default is 0.
      approximant : str, optional
          The waveform approximant to use for the fit function. Default is
          "SEOBNRv4".
  
      Returns
      -------
      float
          The final mass, in solar masses.