java -ea -cp ../../../artifacts/sdk/rt/lib/ext/jfxrt.jar:dist/HelloWorld.jar helloworld.HelloModality
Exception in thread "JavaFX Application Thread" java.lang.IllegalStateException: The window has already been closed
    at com.sun.glass.ui.Window.checkNotClosed(Window.java:284)
    at com.sun.glass.ui.Window.toFront(Window.java:1003)
    at com.sun.javafx.tk.quantum.WindowStage.requestToFront(WindowStage.java:694)
    at com.sun.javafx.tk.quantum.WindowStage.setVisible(WindowStage.java:409)
    at javafx.stage.Window$10.invalidated(Window.java:772)
    at javafx.beans.property.BooleanPropertyBase.markInvalid(BooleanPropertyBase.java:107)
    at javafx.beans.property.BooleanPropertyBase.set(BooleanPropertyBase.java:141)
    at javafx.stage.Window.setShowing(Window.java:809)
    at javafx.stage.Window.hide(Window.java:834)
    at com.sun.javafx.stage.WindowPeerListener.closed(WindowPeerListener.java:93)
    at com.sun.javafx.tk.quantum.GlassWindowEventHandler.run(GlassWindowEventHandler.java:97)
    at com.sun.javafx.tk.quantum.GlassWindowEventHandler.run(GlassWindowEventHandler.java:37)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.tk.quantum.GlassWindowEventHandler.handleWindowEvent(GlassWindowEventHandler.java:118)
    at com.sun.glass.ui.Window.handleWindowEvent(Window.java:1202)
    at com.sun.glass.ui.Window.notifyDestroy(Window.java:1107)
    at com.sun.glass.ui.gtk.GtkWindow._close(Native Method)
    at com.sun.glass.ui.Window.close(Window.java:298)
    at com.sun.javafx.tk.quantum.WindowStage.close(WindowStage.java:596)
    at javafx.stage.Window$10.invalidated(Window.java:788)
    at javafx.beans.property.BooleanPropertyBase.markInvalid(BooleanPropertyBase.java:107)
    at javafx.beans.property.BooleanPropertyBase.set(BooleanPropertyBase.java:141)
    at javafx.stage.Window.setShowing(Window.java:809)
    at javafx.stage.Window.hide(Window.java:834)
    at helloworld.HelloModality$1$1.handle(HelloModality.java:142)
    at helloworld.HelloModality$1$1.handle(HelloModality.java:140)
    at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
    at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:113)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:113)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:113)
    at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
    at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:49)
    at javafx.event.Event.fireEvent(Event.java:202)
    at javafx.scene.Node.fireEvent(Node.java:7855)
    at javafx.scene.control.Button.fire(Button.java:183)
    at com.sun.javafx.scene.control.behavior.ButtonBehavior.mouseReleased(ButtonBehavior.java:183)
    at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:91)
    at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:84)
    at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(CompositeEventHandler.java:218)
    at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:80)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
    at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:113)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:113)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:113)
    at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
    at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
    at javafx.event.Event.fireEvent(Event.java:202)
    at javafx.scene.Scene$MouseHandler.process(Scene.java:3511)
    at javafx.scene.Scene$MouseHandler.process(Scene.java:3342)
    at javafx.scene.Scene$MouseHandler.access$1800(Scene.java:3294)
    at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1582)
    at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2362)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:312)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:237)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:354)
    at com.sun.glass.ui.View.handleMouseEvent(View.java:519)
    at com.sun.glass.ui.View.notifyMouse(View.java:882)
    at com.sun.glass.ui.gtk.GtkApplication._runLoop(Native Method)
    at com.sun.glass.ui.gtk.GtkApplication.access$200(GtkApplication.java:47)
    at com.sun.glass.ui.gtk.GtkApplication$5$1.run(GtkApplication.java:137)
    at java.lang.Thread.run(Thread.java:722)