code: def _get_stddevs(self, C, mag, stddev_types, num_sites):
          
          std = C['c16'] + np.zeros(num_sites)
  
          if mag < 7.4:
              std -= 0.07 * mag
          else:
              std -= 0.518
  
          # only the 'total' standard deviation is supported, therefore the
          # std is always the same for all types
          stddevs = [std for _ in stddev_types]
  
          return stddevs
docs: Return standard deviation as defined in eq.11 page 319.