Merge commit '0ca25191c663ef229f1f475b17899f2017ed6980' into kraken * commit '0ca25191c663ef229f1f475b17899f2017ed6980': Add some comments for zoom methods.
Merge commit '0ca25191c663ef229f1f475b17899f2017ed6980' into kraken * commit '0ca25191c663ef229f1f475b17899f2017ed6980': Add some comments for zoom methods.