code: def _total_flux(self, r_eff, I_eff, n_sersic):
          
          bn = self.b_n(n_sersic)
          return I_eff * r_eff**2 * 2 * np.pi * n_sersic * np.exp(bn) / bn**(2*n_sersic) * scipy.special.gamma(2*n_sersic)
docs: computes total flux of a Sersic profile
  
          :param r_eff: projected half light radius
          :param I_eff: surface brightness at r_eff (in same units as r_eff)
          :param n_sersic: Sersic index
          :return: integrated flux to infinity