@Test
  public void testGetMostRecentEvent() {

    EventManager manager = new EventManagerImpl(2);

    Event e1 = new Event("1", "Event1", Category.INFO, 0);
    Event e2 = new Event("1", "Event2", Category.INFO, 1);

    manager.addEvent(e1);
    manager.addEvent(e2);

    // assert newest to oldest
    assertEquals(e2, manager.getMostRecentEvent("1"));
  }
 @Test
 public void testGetMostRecentEventUnknownSource() {
   EventManager manager = new EventManagerImpl(1);
   assertNull(manager.getMostRecentEvent("unknown value"));
 }