Added the Code Samples

core-java-modules/core-java-concurrency-basic-2/src/test/java/com/baeldung/concurrent/synchronize/BaeldungSychronizedBlockUnitTest.java

@@ -34,4 +34,20 @@ public class BaeldungSychronizedBlockUnitTest {
         assertEquals(1000, BaeldungSynchronizedBlocks.getStaticCount());
     }
 
+    @Test
+    public void givenHoldingTheLock_whenReentrant_thenCanAcquireItItAgain() {
+        Object lock = new Object();
+        synchronized (lock) {
+            System.out.println("First time acquiring it");
+
+            synchronized (lock) {
+                System.out.println("Entering again");
+
+                synchronized (lock) {
+                    System.out.println("And again");
+                }
+            }
+        }
+    }
+
 }