Code cleanup (#1461)

* Code cleanup

* Fix flux tests

* Fix checkstyle errors

* Fix compile error

event-asynchronous/src/main/java/com/iluwatar/event/asynchronous/Event.java

@@ -33,9 +33,9 @@ public class Event implements IEvent, Runnable {
 
   private static final Logger LOGGER = LoggerFactory.getLogger(Event.class);
 
-  private int eventId;
-  private int eventTime;
-  private boolean isSynchronous;
+  private final int eventId;
+  private final int eventTime;
+  private final boolean isSynchronous;
   private Thread thread;
   private boolean isComplete = false;
   private ThreadCompleteListener eventListener;

event-asynchronous/src/main/java/com/iluwatar/event/asynchronous/EventManager.java

@@ -43,8 +43,8 @@ public class EventManager implements ThreadCompleteListener {
   public static final int MAX_ID = MAX_RUNNING_EVENTS;
   public static final int MAX_EVENT_TIME = 1800; // in seconds / 30 minutes.
   private int currentlyRunningSyncEvent = -1;
-  private Random rand;
-  private Map<Integer, Event> eventPool;
+  private final Random rand;
+  private final Map<Integer, Event> eventPool;
 
   private static final String DOES_NOT_EXIST = " does not exist.";