@Override
 public float getValueForNormalization() {
   float sum = 0.0f;
   for (SimWeight stat : subStats) {
     sum += stat.getValueForNormalization();
   }
   return sum / subStats.length;
 }
 @Override
 public void normalize(float queryNorm, float topLevelBoost) {
   for (SimWeight stat : subStats) {
     stat.normalize(queryNorm, topLevelBoost);
   }
 }