void call(L listener);
  }

  /**
   * Adds a listener that will be called using the given executor when events are later {@link
   * #enqueue enqueued} and {@link #dispatch dispatched}.
   */
  public void addListener(L listener, Executor executor) {
    checkNotNull(listener, "listener");
    checkNotNull(executor, "executor");
    listeners.add(new PerListenerQueue<>(listener, executor));
  }

  /**

        for (ProjectExecutionListener listener : listeners) {
            listener.beforeProjectExecution(event);
        }
    }

    public void beforeProjectLifecycleExecution(ProjectExecutionEvent event) throws LifecycleExecutionException {
        for (ProjectExecutionListener listener : listeners) {
            listener.beforeProjectLifecycleExecution(event);
        }
    }

        when:
        def result = parser.parse(classMetaData, listener)

        then:
        format(result.docbook) == '''<para><xref/> <xref/></para>'''
        1 * linkConverter.resolve('someClass', classMetaData, listener) >> document.createElement("xref")
        1 * linkConverter.resolve('otherClass#method(a, b) label', classMetaData, listener) >> document.createElement("xref")
        0 * linkConverter._
    }

    private final GenerationListener listener = new DefaultGenerationListener();

    public ClassDocBuilder(DslDocModel model, JavadocConverter javadocConverter) {
        commentBuilder = new ClassDocCommentBuilder(javadocConverter, listener);
        propertiesBuilder = new ClassDocPropertiesBuilder(javadocConverter, listener);
        methodsBuilder = new ClassDocMethodsBuilder(javadocConverter, listener);

        for (ProjectExecutionListener listener : listeners) {
            listener.beforeProjectExecution(event);
        }
    }

    @Override
    public void beforeProjectLifecycleExecution(ProjectExecutionEvent event) throws LifecycleExecutionException {
        for (ProjectExecutionListener listener : listeners) {
            listener.beforeProjectLifecycleExecution(event);
        }
    }

    RecordingListener listener = new RecordingListener();
    manager.addListener(listener, directExecutor());
    manager.startAsync().awaitHealthy();
    assertTrue(manager.isHealthy());
    assertTrue(listener.healthyCalled);
    assertFalse(listener.stoppedCalled);
    assertTrue(listener.failedServices.isEmpty());
    manager.stopAsync().awaitStopped();

        private final GenerationListener listener;

        private UnknownJavadocTagHandler(DocBookBuilder nodes, Document document, GenerationListener listener) {
            this.nodes = nodes;
            this.document = document;
            this.listener = listener;
        }

        @Override
        public boolean onJavadocTag(String tag, String value) {

    final ClassMetaDataRepository<ClassMetaData> repository = Mock()
    final GenerationListener listener = Mock()
    final JavadocLinkConverter converter = new JavadocLinkConverter(document, nameResolver, linkRenderer, repository)

    def convertsClassNameToLink() {
        when:
        def link = converter.resolve('someName', classMetaData, listener)

        then:
        format(link) == '<someLinkElement/>'

		// Handle request using passed handler.
		handler.ServeHTTP(w, r)
	})

	srv.listenerMutex.Lock()
	srv.Handler = wrappedHandler
	srv.listener = listener
	srv.listenerMutex.Unlock()

	var l net.Listener = listener
	if tlsConfig != nil {
		l = tls.NewListener(listener, tlsConfig)
	}

	serve = func() error {
		return srv.Server.Serve(l)
	}

	return
}

  <!--                                                                  Servlet Listener -->
  <!--                                                                  ================ -->
  <listener>
    <listener-class>org.apache.commons.fileupload.servlet.FileCleanerCleanup</listener-class>
  </listener>

  <!-- ================================================================================= -->