Answer the question and write a bonus simple example about an atomic variable

src/main/java/dev/banking/model/bonus.java

@@ -0,0 +1,32 @@
+package dev.banking.model;
+import java.util.concurrent.atomic.AtomicInteger ;
+public class bonus {
+    private static int normalVariable = 0 ;
+    private static final AtomicInteger atomicVariable  = new AtomicInteger(0) ;
+    public static void main(String[] args) throws InterruptedException{
+        int numberOfThrad = 10 ;
+        int incrementsPerThread = 10000 ;
+        Thread[] threads = new Thread[numberOfThrad] ;
+        Runnable task = () -> {
+            for (int i = 0 ; i < incrementsPerThread ; i ++ )
+            {
+                normalVariable ++ ;
+                atomicVariable.incrementAndGet() ;
+            }
+        };
+        for (int i = 0 ; i < numberOfThrad ; i ++)
+        {
+            threads[i] = new Thread(task) ;
+            threads[i].start();
+        }
+        for (Thread thread : threads)
+        {
+            thread.join();
+        }
+        System.out.println("Expected Value (مقدار مورد انتظار): " + (numberOfThrad * incrementsPerThread));
+        System.out.println("Normal Integer Result (متغیر معمولی): " + normalVariable);
+        System.out.println("Atomic Integer Result (متغیر اتمیک): " + atomicVariable.get());
+
+    }
+
+}