Cc.Director.getInstance().end();调用时出错

Cocos2d-x
#1

Uncaught TypeError: Object function Class() { // All construction is actually done in the init method if (!initializing && this.ctor) this.ctor.apply(this, arguments); } has no method ‘purgeCachedData’ CCDirector.js:580
cc.LabelBMFont.purgeCachedData();

是BUG吗~