@EventHandler method not defined

I’m trying to call a method from server-side via client-side using @EventHanlder but the browser console show me a method not defined. I’m using vaadin-10.0.0.beta9.
The method is called from a custom component.

//main-view.html
<div id="drawerContent" class="drawer-content">
	<app-navigation></app-navigation>
</div>
//app-navigation.html
<vaadin-button on-click="onNavigate">test</vaadin-button>
//AppNavigation.java
@Tag("app-navigation")
@HtmlImport("frontend://src/components/navigation/app-navigation.html")
public class AppNavigation extends PolymerTemplate<AppNavigation.AppNavigationModel> implements AfterNavigationObserver {

	@EventHandler
	private void onNavigate(){
		System.out.println("event");
	}
}

Any suggestion, is this a bug?
If I call the onNavigation in the main-view.html works fine!

Hi,
My bad, the solution is in vaadin doc, [sub-template]
(https://vaadin.com/docs/v10/flow/polymer-templates/tutorial-template-subtemplate.html).