docs: protected void excludeNotCovered(ModifiableDoubleDBIDList candidates, double fmax, ModifiableDoubleDBIDList collect) {
      for(DoubleDBIDListIter it = candidates.iter(); it.valid();) {
        if(it.doubleValue() > fmax) {
          collect.add(it.doubleValue(), it);
          candidates.removeSwap(it.getOffset());
        }
        else {
          it.advance(); // Keep in candidates
        }
      }
    }