Using JavaFX as Headless Browser

Main.java

package org.mikeneck.jfx.js;

import javafx.application.Application;
import netscape.javascript.JSObject;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * @author : mike
 * @since : 13/06/30
 */
public class Main {

    public static void main(String... args) {
        Environment environment = new Environment();
        try {
            environment.setUp();
        } catch (InterruptedException ignored) {
        }
        String script = "(function(){return ['a',2,'c',4,'e'];})();";
        JSObject object = JavaScriptExecutor.executeScript(script, JSObject.class);
        for (int i = 0; i < 5; i++) {
            System.out.println(object.getSlot(i));
        }
        environment.tearDown();
    }

    static class Environment {

        private ExecutorService service = Executors.newFixedThreadPool(1);

        public void setUp () throws InterruptedException {
            service.execute(new StartApplication());
            Thread.sleep(1000L);
        }

        public void tearDown () {
            JavaScriptExecutor.shutdown();
            service.shutdown();
        }

        static class StartApplication implements Runnable {
            @Override
            public void run() {
                Application.launch(JavaScriptExecutor.class);
            }
        }
    }
}

Looking for a Headless JavaFX and tried your class. Can you tell me where to find JavaScriptExecutor.class