code: def get_phi_ss_at_quantile(phi_model, quantile):
      
      # Setup SA coeffs - the backward compatible Python 2.7 way
      coeffs = deepcopy(phi_model.sa_coeffs)
      coeffs.update(phi_model.non_sa_coeffs)
      for imt in coeffs:
          if quantile is None:
              coeffs[imt] = {"a": phi_model[imt]["mean_a"],
                             "b": phi_model[imt]["mean_b"]}
          else:
              coeffs[imt] = {
                  "a": _at_percentile(phi_model[imt]["mean_a"],
                                      phi_model[imt]["var_a"],
                                      quantile),
                  "b": _at_percentile(phi_model[imt]["mean_b"],
                                      phi_model[imt]["var_b"],
                                      quantile)
                  }
      return CoeffsTable(sa_damping=5., table=coeffs)
docs: Returns the phi_ss values at the specified quantile as an instance of
      `class`:: openquake.hazardlib.gsim.base.CoeffsTable - applies to the
      magnitude-dependent cases