code: @Test public void callerDataShouldBeCorrectlySetWithAsynchronousSending() throws Exception {
    String subject="LOGBACK-734";
    buildSMTPAppender("LOGBACK-734",ASYNCHRONOUS);
    smtpAppender.setLayout(buildPatternLayout(DEFAULT_PATTERN));
    smtpAppender.setIncludeCallerData(true);
    smtpAppender.start();
    logger.addAppender(smtpAppender);
    logger.debug("LOGBACK-734");
    logger.error("callerData",new Exception("ShouldBeCorrectlySetWithAsynchronousSending"));
    waitUntilEmailIsSent();
    MimeMultipart mp=verifyAndExtractMimeMultipart(subject);
    String body=GreenMailUtil.getBody(mp.getBodyPart(0));
    assertTrue("actual [" + body + "]",body.contains("DEBUG " + this.getClass().getName() + " - LOGBACK-734"));
  }
  