code: def get_stddevs(self, mag, imt, stddev_types, num_sites):
          
          stddevs = []
          for stddev_type in stddev_types:
              assert stddev_type in self.DEFINED_FOR_STANDARD_DEVIATION_TYPES
              if stddev_type == const.StdDev.TOTAL:
                  sigma = self._get_total_sigma(imt, mag)
                  stddevs.append(sigma + np.zeros(num_sites))
          return stddevs
docs: Returns the total standard deviation