@Test
 public void toQueryString() throws Exception {
   Mailbox mbox =
       MailboxManager.getInstance().getMailboxByAccountId(MockProvisioning.DEFAULT_ACCOUNT_ID);
   AttachmentQuery query = new AttachmentQuery("any");
   Assert.assertEquals(
       "(attachment:any)", ((LuceneQueryOperation) query.compile(mbox, true)).toQueryString());
 }
 @Test
 public void notAny() throws Exception {
   AttachmentQuery query = new AttachmentQuery("any");
   query.setModifier(Query.Modifier.MINUS);
   Assert.assertEquals("Q(attachment:none)", query.toString());
 }