diff --git a/src/main/java/com/fazecast/jSerialComm/NativeSynchronizedInvoker.java b/src/main/java/com/fazecast/jSerialComm/NativeSynchronizedInvoker.java
index b4f1f38..ce9702b 100644
--- a/src/main/java/com/fazecast/jSerialComm/NativeSynchronizedInvoker.java
+++ b/src/main/java/com/fazecast/jSerialComm/NativeSynchronizedInvoker.java
@@ -22,4 +22,24 @@ public class NativeSynchronizedInvoker {
     public static void testNotNativeUnSynchronizedCommPorts() {
         System.out.println(SerialPort.getNotNativeUnSynchronizedCommPorts());
     }
+
+    public void intokeSync() {
+        iAmSynchronized();
+        iAmSynchronized2();
+        iAmNotSynchronized();
+    }
+
+    public synchronized void iAmSynchronized() {
+        System.out.println("hello");
+    }
+
+    public void iAmSynchronized2() {
+        synchronized (this) {
+            System.out.println("hello");
+        }
+    }
+
+    public void iAmNotSynchronized() {
+        System.out.println("hello");
+    }
 }