### Question:
ObjectMessageExceptionHandler implements ExceptionHandler<Throwable>, MessageSourceAware, Ordered { public boolean handle(Throwable exception, ExceptionQueuedEvent event) throws Exception { Assert.state(this.messageSource != null, "MessageSource must not be null"); ExceptionQueuedEventContext eventContext = event.getContext(); FacesContext facesContext = eventContext.getContext(); try { String message = getMessage(exception, FacesUtils.getLocale(facesContext)); facesContext.addMessage(null, new FacesMessage(message)); return true; } catch (NoSuchObjectMessageException e) { return false; } }  boolean handle(Throwable exception, ExceptionQueuedEvent event); void setMessageSource(MessageSource messageSource); int getOrder(); void setOrder(int order);  }### Answer:
@Test public void shouldNeedMessageSource() throws Exception { this.thrown.expect(IllegalStateException.class); this.thrown.expectMessage("MessageSource must not be null"); this.handler.handle(this.exception, this.event); }