### Question:
PrepareMailQueueItem extends AbstractMailQueueItem { @Override public String toString() { return prepareToString().append("context", this.executionContext.getProperties()).toString(); } PrepareMailQueueItem(Iterable<? extends MimeMessage> messages, Session session, MailListener listener,
        String batchId, ExecutionContext executionContext); Iterable<? extends MimeMessage> getMessages(); ExecutionContext getContext(); @Override String toString();  }### Answer:
@Test public void verifyToString() { Session session = Session.getDefaultInstance(new Properties()); MimeMessage message = new MimeMessage(session); String batchId = UUID.randomUUID().toString(); ExecutionContext context = new ExecutionContext(); XWikiContext xContext = new XWikiContext(); xContext.setWikiId("wiki"); context.setProperty(XWikiContext.EXECUTIONCONTEXT_KEY, xContext); PrepareMailQueueItem item = new PrepareMailQueueItem(Arrays.asList(message), session, null, batchId, context); assertEquals("batchId = [" + batchId + "], context = [[xwikicontext] = [{originalWiki=wiki, wiki=wiki}]]", item.toString()); }