@Test
    void startStopNPE() throws Exception {
        // following two classes:
        //   org.eclipse.jetty.util.component.ContainerLifeCycle & org.eclipse.jetty.server.AbstractConnector
        // cause ArmeriaConnector to return values of getHost() and getPort() before
        // its construction completes when DEBUG logging enabled
        final ch.qos.logback.classic.Logger logger1 =
                (ch.qos.logback.classic.Logger) org.slf4j.LoggerFactory.getLogger(
                        org.eclipse.jetty.util.component.ContainerLifeCycle.class.getName());
        final ch.qos.logback.classic.Logger logger2 =
                (ch.qos.logback.classic.Logger) org.slf4j.LoggerFactory.getLogger(
                        org.eclipse.jetty.server.AbstractConnector.class.getName());
        final ch.qos.logback.classic.Level logger1Level = logger1.getLevel();
        final ch.qos.logback.classic.Level logger2Level = logger2.getLevel();
        try {
            logger1.setLevel(ch.qos.logback.classic.Level.DEBUG);
            logger2.setLevel(ch.qos.logback.classic.Level.DEBUG);

            startStop();
        } finally {
            logger1.setLevel(logger1Level);
            logger2.setLevel(logger2Level);
        }
    }
Test NPE (Issue #2688).
CAUTION: This test is specific to configured logger (Logback). Change it when the underlying logger
changes.
jetty/jetty11/src/test/java/com/linecorp/armeria/server/jetty/JettyServiceStartupTest.java