diff --git a/README.md b/README.md
index de3a421..4d0116e 100644
--- a/README.md
+++ b/README.md
@@ -47,7 +47,6 @@ The purpose of **Inspectable Wrappers** is to provide a standard for wrapper cha
 ## 🌰 Demo
 
 Below use the `Executor Wrapper` to demonstrate the usage.
-(Runnable demo codes in project: [`Demo.java`](src/test/java/io/foldright/demo/Demo.java))
 
 ### wrapper implementations in your application code
 
@@ -82,7 +81,7 @@ public class LazyExecutorWrapper implements Executor, Wrapper<Executor>, Attacha
 
   @Override
   public void execute(Runnable command) {
-    System.out.println("I'm lazy, sleep before work");
+    System.out.println("I'm lazy, sleep before work.");
     sleep();
 
     executor.execute(command);
@@ -112,39 +111,55 @@ public class LazyExecutorWrapper implements Executor, Wrapper<Executor>, Attacha
 ```java
 public class Demo {
   public static void main(String[] args) {
-    ////////////////////////////////////////
-    // prepare executor instance and wrappers
-    ////////////////////////////////////////
-
-    final Executor executor = Runnable::run;
-
-    final LazyExecutorWrapper lazy = new LazyExecutorWrapper(executor);
-    lazy.setAttachment("busy", "very, very busy!");
-
-    final Executor chatty = new ChattyExecutorWrapper(lazy);
+    final Executor executor = buildExecutorChain();
 
     ////////////////////////////////////////
-    // inspect the wrapper chain
+    // inspect the executor(wrapper chain)
     ////////////////////////////////////////
 
-    System.out.println("Is chatty executor LazyExecutor? " +
-        Wrapper.isInstanceOf(chatty, LazyExecutorWrapper.class));
+    System.out.println("Is executor lazy? " +
+        Wrapper.isInstanceOf(executor, LazyExecutorWrapper.class));
     // print true
 
-    String busy = Wrapper.getAttachment(chatty, "busy");
-    System.out.println("Is chatty executor busy? " + busy);
+    String busy = Wrapper.getAttachment(executor, "busy");
+    System.out.println("Is executor busy? " + busy);
     // print "very, very busy!"
 
     ////////////////////////////////////////
-    // call executor
+    // call executor(wrapper chain)
     ////////////////////////////////////////
 
     System.out.println();
-    chatty.execute(() -> System.out.println("work!"));
+    executor.execute(() -> System.out.println("I'm working."));
+  }
+
+  /**
+   * prepare executor instances/wrappers, build the executor/wrapper chain
+   **/
+  private static Executor buildExecutorChain() {
+    final Executor base = Runnable::run;
+
+    final LazyExecutorWrapper lazy = new LazyExecutorWrapper(base);
+    lazy.setAttachment("busy", "very, very busy!");
+
+    return new ChattyExecutorWrapper(lazy);
   }
 }
+
+/*
+demo output:
+
+Is executor lazy? true
+Is executor busy? very, very busy!
+
+BlaBlaBla...
+I'm lazy, sleep before work.
+I'm working.
+ */
 ```
 
+> Runnable demo codes in project: [`Demo.java`](src/test/java/io/foldright/demo/Demo.java)
+
 ## 🍼 Java API Docs
 
 The current version Java API documentation: <https://foldright.io/inspectable-wrappers/apidocs/>
diff --git a/src/test/java/io/foldright/demo/Demo.java b/src/test/java/io/foldright/demo/Demo.java
index 8e23321..de74061 100644
--- a/src/test/java/io/foldright/demo/Demo.java
+++ b/src/test/java/io/foldright/demo/Demo.java
@@ -7,34 +7,48 @@
 
 public class Demo {
     public static void main(String[] args) {
-        ////////////////////////////////////////
-        // prepare executor instance and wrappers
-        ////////////////////////////////////////
-
-        final Executor executor = Runnable::run;
-
-        final LazyExecutorWrapper lazy = new LazyExecutorWrapper(executor);
-        lazy.setAttachment("busy", "very, very busy!");
-
-        final Executor chatty = new ChattyExecutorWrapper(lazy);
+        final Executor executor = buildExecutorChain();
 
         ////////////////////////////////////////
-        // inspect the wrapper chain
+        // inspect the executor(wrapper chain)
         ////////////////////////////////////////
 
-        System.out.println("Is chatty executor LazyExecutor? " +
-                Wrapper.isInstanceOf(chatty, LazyExecutorWrapper.class));
+        System.out.println("Is executor lazy? " +
+                Wrapper.isInstanceOf(executor, LazyExecutorWrapper.class));
         // print true
 
-        String busy = Wrapper.getAttachment(chatty, "busy");
-        System.out.println("Is chatty executor busy? " + busy);
+        String busy = Wrapper.getAttachment(executor, "busy");
+        System.out.println("Is executor busy? " + busy);
         // print "very, very busy!"
 
         ////////////////////////////////////////
-        // call executor
+        // call executor(wrapper chain)
         ////////////////////////////////////////
 
         System.out.println();
-        chatty.execute(() -> System.out.println("work!"));
+        executor.execute(() -> System.out.println("I'm working."));
+    }
+
+    /**
+     * prepare executor instances/wrappers, build the executor/wrapper chain
+     **/
+    private static Executor buildExecutorChain() {
+        final Executor base = Runnable::run;
+
+        final LazyExecutorWrapper lazy = new LazyExecutorWrapper(base);
+        lazy.setAttachment("busy", "very, very busy!");
+
+        return new ChattyExecutorWrapper(lazy);
     }
 }
+
+/*
+demo output:
+
+Is executor lazy? true
+Is executor busy? very, very busy!
+
+BlaBlaBla...
+I'm lazy, sleep before work.
+I'm working.
+ */
diff --git a/src/test/java/io/foldright/demo/LazyExecutorWrapper.java b/src/test/java/io/foldright/demo/LazyExecutorWrapper.java
index 8ae589b..a31bb14 100644
--- a/src/test/java/io/foldright/demo/LazyExecutorWrapper.java
+++ b/src/test/java/io/foldright/demo/LazyExecutorWrapper.java
@@ -21,7 +21,7 @@ public LazyExecutorWrapper(Executor executor) {
 
     @Override
     public void execute(Runnable command) {
-        System.out.println("I'm lazy, sleep before work");
+        System.out.println("I'm lazy, sleep before work.");
         sleep();
 
         executor.execute(command);