### Question:
KieSiftingAppender extends SiftingAppender { @Override protected void append(ILoggingEvent eventObject) { if (!eventObject.getMDCPropertyMap().isEmpty()) { StringBuilder sb = new StringBuilder(); sb.append(eventObject.getLevel()).append(" ").append(eventObject.getFormattedMessage()); OutputSharedMap.addMsgToLog(eventObject.getMDCPropertyMap().get(MavenConfig.COMPILATION_ID), sb.toString()); } }    }### Answer:
@Test public void appendTest() { String compilationID = "80dbc168-a1fe-499d-a414-d4a37d13d100-1516620517065-0"; String[] args = new String[]{}; LoggingEvent event = new LoggingEvent("org.kie.workbench.common.services.backend.logback.appender.KieSiftingAppenderTest", (ch.qos.logback.classic.Logger) logger, Level.INFO, "I'm a beatiful test message :)", null, args); Map<String, String> mdcMap = new HashMap<>(); mdcMap.put(MavenConfig.COMPILATION_ID, compilationID); event.setMDCPropertyMap(mdcMap); KieSiftingAppenderProxy appender = new KieSiftingAppenderProxy(); appender.appendTest(event); List<String> msgs = OutputSharedMap.getLog(compilationID); assertThat(msgs).hasSize(1); String msg = msgs.get(0); assertThat(msg).isEqualTo("INFO I'm a beatiful test message :)"); }