IMPORTANT NOTICE: YOU ARE NOT READING THE LATEST VERSION. THIS VERSION IS PROVIDED FOR YOUR REFERENCE OF THE TRANSITIONAL API. THIS API ORIGINALLY AIMED TO SUPPORT BOTH NEW AND OLD API, AND HENCE IS VERY CONFUSING FOR SOME USERS. AS SUCH, WE DECIDED TO SEPARATE OLD AND NEW API INTO V1 AND V2. THIS API, WHILE STILL WORKS, WILL BE REMOVED IN FUTURE. YOU ARE RECOMMENDED TO UPGRADE TO V2 IF YOU ARE STILL USING THIS API.