@Override
    public WebServer getWebServer(ServletContextInitializer... initializers) {
        for (ServletContextInitializer i : initializers) {
            try {
                if (handler.getServletContext() == null) {
                    throw new WebServerException("Attempting to initialize ServletEmbeddedWebServer without ServletContext in Handler", null);
                }
                i.onStartup(handler.getServletContext());
            } catch (ServletException e) {
                throw new WebServerException("Could not initialize Servlets", e);
            }
        }
        return this;
    }
@Test
    void getWebServer_callsInitializers() {
        ServerlessServletEmbeddedServerFactory factory = new ServerlessServletEmbeddedServerFactory();
        factory.getWebServer(new ServletContextInitializer() {
            @Override
            public void onStartup(ServletContext servletContext) throws ServletException {
                if (servletContext == null) {
                    fail("Null servlet context");
                }
            }
        });
    }