docs: public void pairsSortedByKey(final IntArrayList keyList, final ObjectArrayList valueList) {
  	keys(keyList);
  	keyList.sort();
  	valueList.setSize(keyList.size());
  	for (int i=keyList.size(); --i >= 0; ) {
  		valueList.setQuick(i,get(keyList.getQuick(i)));
  	}
  }