docs: public static int centroids(Relation<? extends NumberVector> rel, List<? extends Cluster<?>> clusters, NumberVector[] centroids, NoiseHandling noiseOption) {
      assert (centroids.length == clusters.size());
      int ignorednoise = 0;
      Iterator<? extends Cluster<?>> ci = clusters.iterator();
      for(int i = 0; ci.hasNext(); i++) {
        Cluster<?> cluster = ci.next();
        if(cluster.size() <= 1 || cluster.isNoise()) {
          switch(noiseOption){
          case IGNORE_NOISE:
            ignorednoise += cluster.size();
          case TREAT_NOISE_AS_SINGLETONS:
            centroids[i] = null;
            continue;
          case MERGE_NOISE:
            break; // Treat as cluster below
          }
        }
        centroids[i] = ModelUtil.getPrototypeOrCentroid(cluster.getModel(), rel, cluster.getIDs());
      }
      return ignorednoise;
    }