diff -r 6242ffbcfd16 -r b547f8f663f5 xhr4j/src/test/java/org/netbeans/html/xhr4j/JsonFX.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/xhr4j/src/test/java/org/netbeans/html/xhr4j/JsonFX.java	Mon Feb 29 05:25:31 2016 +0100
@@ -0,0 +1,126 @@
+/**
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
+ *
+ * Copyright 2013-2014 Oracle and/or its affiliates. All rights reserved.
+ *
+ * Oracle and Java are registered trademarks of Oracle and/or its affiliates.
+ * Other names may be trademarks of their respective owners.
+ *
+ * The contents of this file are subject to the terms of either the GNU
+ * General Public License Version 2 only ("GPL") or the Common
+ * Development and Distribution License("CDDL") (collectively, the
+ * "License"). You may not use this file except in compliance with the
+ * License. You can obtain a copy of the License at
+ * http://www.netbeans.org/cddl-gplv2.html
+ * or nbbuild/licenses/CDDL-GPL-2-CP. See the License for the
+ * specific language governing permissions and limitations under the
+ * License.  When distributing the software, include this License Header
+ * Notice in each file and include the License file at
+ * nbbuild/licenses/CDDL-GPL-2-CP.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the GPL Version 2 section of the License file that
+ * accompanied this code. If applicable, add the following below the
+ * License Header, with the fields enclosed by brackets [] replaced by
+ * your own identifying information:
+ * "Portions Copyrighted [year] [name of copyright owner]"
+ *
+ * Contributor(s):
+ *
+ * The Original Software is NetBeans. The Initial Developer of the Original
+ * Software is Oracle. Portions Copyright 2013-2014 Oracle. All Rights Reserved.
+ *
+ * If you wish your version of this file to be governed by only the CDDL
+ * or only the GPL Version 2, indicate your decision by adding
+ * "[Contributor] elects to include this software in this distribution
+ * under the [CDDL or GPL Version 2] license." If you do not indicate a
+ * single choice of license, a recipient has the option to distribute
+ * your version of this file under either the CDDL, the GPL Version 2 or
+ * to extend the choice of license to its licensees as provided above.
+ * However, if you add GPL Version 2 code and therefore, elected the GPL
+ * Version 2 license, then the option applies only if the new code is
+ * made subject to such option by the copyright holder.
+ */
+package org.netbeans.html.xhr4j;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import javafx.application.Platform;
+import org.netbeans.html.boot.impl.FnContext;
+import org.netbeans.html.boot.spi.Fn;
+import org.testng.ITest;
+import org.testng.annotations.Test;
+
+/**
+ *
+ * @author Jaroslav Tulach
+ */
+public final class JsonFX implements ITest, Runnable {
+    private final Fn.Presenter p;
+    private final Method m;
+    private Object result;
+    private Object inst;
+    private int count;
+
+    JsonFX(Fn.Presenter p, Method m) {
+        this.p = p;
+        this.m = m;
+    }
+
+    @Override
+    public String getTestName() {
+        return m.getName();
+    }
+
+    @Test
+    public synchronized void executeTest() throws Exception {
+        if (result == null) {
+            Platform.runLater(this);
+            wait();
+        }
+        if (result instanceof Exception) {
+            throw (Exception)result;
+        }
+        if (result instanceof Error) {
+            throw (Error)result;
+        }
+    }
+
+    @Override
+    public synchronized void run() {
+        boolean notify = true;
+        try {
+            FnContext.currentPresenter(p);
+            if (inst == null) {
+                inst = m.getDeclaringClass().newInstance();
+            }
+            System.err.println("invoke " + m + " with " + count);
+            result = m.invoke(inst);
+            if (result == null) {
+                result = this;
+            }
+        } catch (InvocationTargetException ex) {
+            Throwable r = ex.getTargetException();
+            if (r instanceof InterruptedException) {
+                if (count++ < 100) {
+                    notify = false;
+                    try {
+                        Thread.sleep(100);
+                    } catch (Exception ex1) {
+                        // ignore and continue
+                    }
+                    Platform.runLater(this);
+                    return;
+                }
+            }
+            result = r;
+        } catch (Exception ex) {
+            result = ex;
+        } finally {
+            if (notify) {
+                notifyAll();
+            }
+            FnContext.currentPresenter(null);
+        }
+    }
+    
+}