function fnSortSemanticContent(oControl1, oControl2) {

		var iSortIndex1 = oControl1.data("sortIndex");
		var iSortIndex2 = oControl2.data("sortIndex");

		if ((typeof iSortIndex1 === 'undefined') ||
				(typeof iSortIndex2 === 'undefined')) {
			Log.warning("sortIndex missing", this);
			return null;
		}

		return (iSortIndex1 - iSortIndex2);
	}
Destroys all cached instances of the {@link sap.ui.core.InvisibleText} control.
@private