e.pop2();
    private void emitSetCallback(ClassEmitter ce, int[] keys) {        final CodeEmitter e = ce.begin_method(Constants.ACC_PUBLIC, SET_CALLBACK, null);        e.load_this();        e.load_arg(1);        e.load_arg(0);        e.process_switch(keys, new ProcessSwitchCallback() {            public void processCase(int key, Label end) {                e.checkcast(callbackTypes[key]);                e.putfield(getCallbackField(key));                e.goTo(end);            }            public void processDefault() {                // TODO: error?                e.pop2(); // stack height            }        });        e.return_value();        e.end_method();    }