* for each class that is used in a list</li>
 * </ul>
 * Code is written like it could be generated, with default behaviour to be overridden when necessary.
 * This is particularly the case for <code>Object get<i>Classname</i>Key( <i>Classname</i> <i>classname</i> )</code>
 * method, which by default return the object itself and is expected to be overridden to calculate better suited key
 * value.
 *