code: def get_mean_and_stddevs(self, sites, rup, dists, imt, stddev_types):
          
          # extract dictionaries of coefficients specific to required
          # intensity measure type and for PGA
          C = self.COEFFS[imt]
          # For inslab GMPEs the correction term is fixed at -0.3
          dc1 = -0.3
          C_PGA = self.COEFFS[PGA()]
          # compute median pga on rock (vs30=1000), needed for site response
          # term calculation
          pga1000 = np.exp(
              self._compute_pga_rock(C_PGA, dc1, sites, rup, dists))
          mean = (self._compute_magnitude_term(C, dc1, rup.mag) +
                  self._compute_distance_term(C, rup.mag, dists) +
                  self._compute_focal_depth_term(C, rup) +
                  self._compute_forearc_backarc_term(C, sites, dists) +
                  self._compute_site_response_term(C, sites, pga1000))
          stddevs = self._get_stddevs(C, stddev_types, len(sites.vs30))
          return mean, stddevs
docs: See :meth:`superclass method
          <.base.GroundShakingIntensityModel.get_mean_and_stddevs>`
          for spec of input and result values.