MessageToClientManager { List<Object> getArrayList() { return new ArrayList<>(); }  abstract Map<String, Object> getSessionBeans(T session); MessageToClient createMessageToClient(MessageFromClient message, T session);  }
@Test public void testGetArrayList() throws Exception { System.out.println("getArrayList"); List<Object> arrayList = instance.getArrayList(); assertThat(arrayList).isNotNull(); }