Update README.md

Author: iluwatar

callback/README.md

@@ -9,22 +9,26 @@ tags:
 ---
 
 ## Intent
-Callback is a piece of executable code that is passed as an argument to other code, which is expected to call back 
-(execute) the argument at some convenient time.
+
+Callback is a piece of executable code that is passed as an argument to other code, which is 
+expected to call back (execute) the argument at some convenient time.
 
 ## Explanation
 
 Real world example
 
-> We need to be notified after executing task has finished. We pass a callback method for the executor and wait for it to call back on us.     
+> We need to be notified after executing task has finished. We pass a callback method for 
+> the executor and wait for it to call back on us.     
 
 In plain words
 
 > Callback is a method passed to the executor which will be called at defined moment. 
 
 Wikipedia says
 
-> In computer programming, a callback, also known as a "call-after" function, is any executable code that is passed as an argument to other code; that other code is expected to call back (execute) the argument at a given time.
+> In computer programming, a callback, also known as a "call-after" function, is any executable 
+> code that is passed as an argument to other code; that other code is expected to call 
+> back (execute) the argument at a given time.
 
 **Programmatic Example**
 
@@ -61,21 +65,23 @@ public final class SimpleTask extends Task {
 }
 ```
 
-Finally here's how we execute a task and receive a callback when it's finished.
+Finally, here's how we execute a task and receive a callback when it's finished.
 
 ```java
     var task = new SimpleTask();
     task.executeWith(() -> LOGGER.info("I'm done now."));
 ```
 
 ## Class diagram
+
 ![alt text](./etc/callback.png "Callback")
 
 ## Applicability
+
 Use the Callback pattern when
 
 * when some arbitrary synchronous or asynchronous action must be performed after execution of some defined activity.
 
 ## Real world examples
 
-* [CyclicBarrier](http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/CyclicBarrier.html#CyclicBarrier%28int,%20java.lang.Runnable%29) constructor can accept callback that will be triggered every time when barrier is tripped.
+* [CyclicBarrier](http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/CyclicBarrier.html#CyclicBarrier%28int,%20java.lang.Runnable%29) constructor can accept a callback that will be triggered every time a barrier is tripped.

callback/etc/callback.png

@@ -8,11 +8,6 @@ package com.iluwatar.callback {
   interface Callback {
     + call() {abstract}
   }
-  class LambdasApp {
-    - LOGGER : Logger {static}
-    - LambdasApp()
-    + main(args : String[]) {static}
-  }
   class SimpleTask {
     - LOGGER : Logger {static}
     + SimpleTask()