Executions.getCurrent().sendRedirect() method is not working without http

Index.zul

<zk>
  <window border="normal" title="hello" apply="pkg$.TestComposer">
 
  <div>Welcome to ZK Fiddle , run it right now!</div>
 
<button id="btn" label="Click Me To Evalute Event Binding With Composer" />
 
    <button id="btn2" label="New Window no menubar" />
 
  </window>
</zk>

TestComposer .java

package

pkg$

;

import org.zkoss.zk.ui.*;
import org.zkoss.zk.ui.event.*;
import org.zkoss.zk.ui.util.*;
import org.zkoss.zk.ui.ext.*;
import org.zkoss.zk.au.*;
import org.zkoss.zk.au.out.*;
import org.zkoss.zul.*;

public class TestComposer extends GenericForwardComposer{

public void doAfterCompose(Component comp) throws Exception {
super.doAfterCompose(comp);

}

public void onClick$btn(Event e) throws InterruptedException{
         Executions.getCurrent().sendRedirect("http://www.google.com", "_blank");
}

  public void onClick$btn2(Event e) throws InterruptedException{
         Clients.evalJavaScript("window.open('http://www.google.com','','top=100,left=200,height=600,width=800,scrollbars=1,resizable=1')");
}
}