code: private void initializeBuiltInImplementors() {
  		builtInImplementors.put(ArrayList.class, new ArrayListImplementor());
  		builtInImplementors.put(ConcurrentHashMap.class, new ConcurrentHashMapImplementor());
  		builtInImplementors.put(GregorianCalendar.class, new GregorianCalendarImplementor());
  		builtInImplementors.put(HashMap.class, new HashMapImplementor());
  		builtInImplementors.put(HashSet.class, new HashSetImplementor());
  		builtInImplementors.put(LinkedList.class, new LinkedListImplementor());
  		builtInImplementors.put(TreeMap.class, new TreeMapImplementor());
  		allImplementors.putAll(builtInImplementors);
  	}
docs: Initialise a set of built in CloneImplementors for commonly used JDK types