findItems = (aItemItems) => {
			aItemItems.forEach((oItem) => {
				if (!this._isMenuItemGroup(oItem)) {
					aItems.push(oItem);
				} else {
					findItems(oItem.getItems());
				}
			});
		}
Returns list of items stored in <code>items</code> aggregation. If any items are part of a group,
it returns the individual items within the group instead of the group item itself.

@returns {sap.m.MenuItem} List of all menu items
@private