TestFX 3 ( extends GuiTest , @Override  getRootNode())
What is TestFX 4?
    - more in line with JavaFX bootstrapping (extends ApplicationTest)
    - ApplicationTest extends FxRobot (clickon, write , drag etc ..sim user actions    )
      implements ApplicationFixture  (init, start, stop)
    - launch(Class<? extends Application> ..)
    - can use othertesting frameworks, not just Junit
    - new node query API.
    - Java 8 lambdas
    - headless testing using Monocle (thus can use on CI server configurations )

POM - alpha 4.0.4 March 2016 (> 1 year)
- SpringApplicationBuilder.headless(false)

    public static <T extends Node> void verifyThat(NodeQuery nodeQuery,
                                                   Predicate<T> nodePredicate) {
        verifyThatImpl(emptyReason(), toNode(nodeQuery), toNodeMatcher(nodePredicate));
    }
