fnAnimCallback = function(iTimestamp) {
				iTimestampInitial ||= iTimestamp;
				if (iTimestamp !== iTimestampInitial) {
					fnCallback();
				} else {
					window.requestAnimationFrame(fnAnimCallback);
				}
			}
CSS Transition helper
@param {HTMLElement} oElement - Element
@param {Function} fnCallback - The function should start animation process (e.g. by adding class to the element)
@return {Promise} Returns a Promise performing the animation