code: def get_mean_and_stddevs(self, sites, rup, dists, imt, stddev_types):
          
  
          C = self.COEFFS[imt]
          C_PGA = self.COEFFS[PGA()]
          C_AMP = self.AMP_COEFFS[imt]
  
          # Gets the PGA on rock - need to convert from g to cm/s/s
          pga_rock = self._compute_pga_rock(C_PGA, rup.mag, dists.rjb) * 980.665
          # Get the mean ground motion value
          mean = (self._compute_nonlinear_magnitude_term(C, rup.mag) +
                  self._compute_magnitude_distance_term(C, dists.rjb, rup.mag) +
                  self._get_site_amplification(C_AMP, sites.vs30, pga_rock))
  
          # Get standard deviations
          stddevs = self._get_stddevs(C, stddev_types, dists.rjb.shape)
          return mean, stddevs
docs: See :meth:`superclass method
          <.base.GroundShakingIntensityModel.get_mean_and_stddevs>`
          for spec of input and result values.
  
          Implements equation 14 of Hong & Goda (2007)