* @param {String/Number} key The key or index of the item.
* @return {Object} If the item is found, returns the item. If the item was not found, returns <tt>undefined</tt>.
* If an item was found, but is a Class, returns <tt>null</tt>.
* @param {String/Number} key The key or index of the item.
* @return {Object} If the item is found, returns the item. If the item was not found, returns <tt>undefined</tt>.
* If an item was found, but is a Class, returns <tt>null</tt>.