Index: src/java/org/apache/hadoop/HelloWorld.java
===================================================================
--- src/java/org/apache/hadoop/HelloWorld.java	(revision 0)
+++ src/java/org/apache/hadoop/HelloWorld.java	(revision 0)
@@ -0,0 +1,21 @@
+package org.apache.hadoop;
+
+/**
+ * An annotation example.
+ */
+@Audience(Audience.Type.PUBLIC)
+public class HelloWorld {
+  @Audience(Audience.Type.LIMITED_PRIVATE)
+  public HelloWorld() {
+  }
+  
+  @Audience(Audience.Type.PUBLIC)
+  public String toString() {
+    return getClass().getSimpleName();
+  }
+
+  /** main */
+  public static void main(String[] args) {
+    System.out.println(new HelloWorld());
+  }
+}
Index: src/java/org/apache/hadoop/Audience.java
===================================================================
--- src/java/org/apache/hadoop/Audience.java	(revision 0)
+++ src/java/org/apache/hadoop/Audience.java	(revision 0)
@@ -0,0 +1,12 @@
+package org.apache.hadoop;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.Inherited;
+
+@Documented
+@Inherited
+public @interface Audience {
+  public enum Type {PUBLIC, LIMITED_PRIVATE, PRIVATE};
+
+  Type value() default Type.PRIVATE;
+}
\ No newline at end of file