docs: private void clinkstep8(DBIDRef id, DBIDArrayIter it, int n, WritableDBIDDataStore pi, WritableDoubleDataStore lambda, WritableDoubleDataStore m) {
      DBIDVar p_i = DBIDUtil.newVar(), pp_i = DBIDUtil.newVar();
      for(it.seek(0); it.getOffset() < n; it.advance()) {
        p_i.from(pi, it); // p_i = pi[i]
        pp_i.from(pi, p_i); // pp_i = pi[pi[i]]
        if(DBIDUtil.equal(pp_i, id) && lambda.doubleValue(it) >= lambda.doubleValue(p_i)) {
          pi.putDBID(it, id);
        }
      }
    }