public ScreenshotTest screenshotTest(AppState... initialStates){
        return new ScreenshotTest(initialStates);
    }
Initialises a screenshot test. The resulting object should be configured (if neccessary) and then started
by calling {@link ScreenshotTest#run()}.
@param initialStates
@return
jme3-screenshot-tests/src/main/java/org/jmonkeyengine/screenshottests/testframework/ScreenshotTestBase.java