added push example

reference-examples/dsl/src/main/java/com/fluxtion/example/reference/dsl/PushSample.java

@@ -0,0 +1,23 @@
+package com.fluxtion.example.reference.dsl;
+
+import com.fluxtion.compiler.Fluxtion;
+import com.fluxtion.compiler.builder.dataflow.DataFlow;
+
+public class PushSample {
+    public static void main(String[] args) {
+        var processor = Fluxtion.interpret(c ->
+                DataFlow.subscribe(String.class)
+                        .push(new MyPushTarget()::updated)
+        );
+        processor.init();
+
+        processor.onEvent("AAA");
+        processor.onEvent("BBB");
+    }
+
+    public static class MyPushTarget{
+        public void updated(String in){
+            System.out.println("received push: " + in);
+        }
+    }
+}