@BeforeAll
    static void setUpHttpServer() throws Exception {
        // Specify the folder from which files will be served
        httpServerPort = findAvailablePort();
        httpServer = new Server(httpServerPort);

        ResourceHandler resourceHandler = new ResourceHandler();
        resourceHandler.setDirAllowed(true);
        // TODO when using jetty 12:
        // resourceHandler.setBaseResourceAsString("src/test/resources/test-files")        
        resourceHandler.setBaseResource(new PathResource(Paths.get("src", "test", "resources", "test-files")));
        httpServer.setHandler(resourceHandler);
        httpServer.start();

        httpServerUrl = "http://" + InetAddress
                .getByName("localhost")
                .getHostAddress() + ":" + httpServerPort;
    }
This test will start an HTTP server using jetty.
Then it will start Tika Pipes Grpc service.
Then it will, using a bidirectional stream of data, send urls to the
HTTP fetcher whilst simultaneously receiving parsed output as they parse.
tika-grpc/src/test/java/org/apache/tika/pipes/grpc/PipesBiDirectionalStreamingIntegrationTest.java