code: // Licensed to the Software Freedom Conservancy (SFC) under one
  // or more contributor license agreements.  See the NOTICE file
  // distributed with this work for additional information
  // regarding copyright ownership.  The SFC licenses this file
  // to you under the Apache License, Version 2.0 (the
  // "License"); you may not use this file except in compliance
  // with the License.  You may obtain a copy of the License at
  //
  //   http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing,
  // software distributed under the License is distributed on an
  // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  // KIND, either express or implied.  See the License for the
  // specific language governing permissions and limitations
  // under the License.
  
  package org.openqa.selenium.grid.web;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  
  import java.net.MalformedURLException;
  import java.net.URISyntaxException;
  import org.junit.jupiter.api.Test;
  import org.openqa.selenium.netty.server.SimpleHttpServer;
  import org.openqa.selenium.remote.http.HttpClient;
  import org.openqa.selenium.remote.http.HttpHandler;
  import org.openqa.selenium.remote.http.HttpMethod;
  import org.openqa.selenium.remote.http.HttpRequest;
  import org.openqa.selenium.remote.http.HttpResponse;
  import org.openqa.selenium.remote.tracing.DefaultTestTracer;
  import org.openqa.selenium.remote.tracing.Tracer;
  
  class ReverseProxyHandlerTest {
    private Tracer tracer = DefaultTestTracer.createTracer();
    private HttpClient.Factory factory = HttpClient.Factory.createDefault();
  
    @Test
    void shouldForwardRequestsToEndPoint()
        throws MalformedURLException, URISyntaxException, InterruptedException {
      try (SimpleHttpServer server = new SimpleHttpServer()) {
        server.registerEndpoint(HttpMethod.GET, "/ok", SimpleHttpServer.ECHO_HEADERS_HANDLER);
  
        HttpHandler handler =
            new ReverseProxyHandler(tracer, factory.createClient(server.baseUri().toURL()));
        HttpRequest req = new HttpRequest(HttpMethod.GET, "/ok");
        req.addHeader("X-Cheese", "Cake");
        HttpResponse response = handler.execute(req);
  
        // HTTP headers are case insensitive.
        assertEquals("Cake", response.getHeader("x-cheese"));
      }
    }
  }
  