def test_searchSentBefore(self):
        """
        L{imap4.IMAP4Server.search_SENTBEFORE} returns True if the message date
        is earlier than the query date.
        """
        self.assertFalse(
            self.server.search_SENTBEFORE(self.earlierQuery, self.seq, self.msg))
        self.assertTrue(
            self.server.search_SENTBEFORE(self.laterQuery, self.seq, self.msg))

        L{imap4.IMAP4Server.search_SENTBEFORE} returns True if the message date
        is earlier than the query date.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/mail/test/test_imap.py