Why doesn't adding an EventHandler from this (error) work?

Question

Java

Why doesn't this work? (gives an error)

Class UIItem implements EventHandler<MouseEvent>{
    public  <E extends Event> void addEventHandler(EventType<E> eventType){
            treeItem.addEventHandler(eventType, this);
    }
    @Override
    public void handle(MouseEvent mouseEvent) {
        System.out.println("EVENT");
    }
}

And it doesn't work (doesn't display "EVENT")

Class UIItem implements EventHandler<MouseEvent>{
    public  <E extends Event> void addEventHandler(EventType<E> eventType){
            treeItem.addEventHandler(eventType, (EventHandler<E>) this);

    }
    @Override
    public void handle(MouseEvent mouseEvent) {
        System.out.println("EVENT");
    }
}

PS Problem Solving

Class UIItem implements EventHandler<MouseEvent>{
    public  <E extends Event> void addEventHandler(EventType<E> eventType){
            treeItem.getValue().addEventHandler(eventType, (EventHandler<E>) this);

    }
    @Override
    public void handle(MouseEvent mouseEvent) {
        System.out.println("EVENT");
    }
}