[JAVA-13958] Minor style changes + aligned code with article (#12889)

Co-authored-by: panagiotiskakos <panagiotis.kakos@libra-is.com>

core-java-modules/core-java-concurrency-simple/src/test/java/com/baeldung/concurrent/waitandnotify/NetworkIntegrationTest.java

@@ -16,24 +16,24 @@ public class NetworkIntegrationTest {
     private final ByteArrayOutputStream outContent = new ByteArrayOutputStream();
     private final ByteArrayOutputStream errContent = new ByteArrayOutputStream();
     private String expected;
-    
+
     @Before
     public void setUpStreams() {
         System.setOut(new PrintStream(outContent));
         System.setErr(new PrintStream(errContent));
     }
-    
+
     @Before
     public void setUpExpectedOutput() {
         StringWriter expectedStringWriter = new StringWriter();
-        
+
         PrintWriter printWriter = new PrintWriter(expectedStringWriter);
         printWriter.println("First packet");
         printWriter.println("Second packet");
         printWriter.println("Third packet");
         printWriter.println("Fourth packet");
         printWriter.close();
-        
+
         expected = expectedStringWriter.toString();
     }
 
@@ -42,25 +42,26 @@ public class NetworkIntegrationTest {
         System.setOut(null);
         System.setErr(null);
     }
-    
+
     @Test
     public void givenSenderAndReceiver_whenSendingPackets_thenNetworkSynchronized() {
         Data data = new Data();
         Thread sender = new Thread(new Sender(data));
         Thread receiver = new Thread(new Receiver(data));
-        
+
         sender.start();
         receiver.start();
-        
+
         //wait for sender and receiver to finish before we test against expected
         try {
             sender.join();
             receiver.join();
         } catch (InterruptedException e) {
-            Thread.currentThread().interrupt(); 
-            System.out.println("Thread Interrupted");
+            Thread.currentThread()
+                .interrupt();
+            System.err.println("Thread Interrupted");
         }
-        
+
         assertEquals(expected, outContent.toString());
     }
 }