ClassLoader customClassLoader = new URLClassLoader(new URL[0], null) {
            @Override
            public Class<?> loadClass(String name) throws ClassNotFoundException {
                if ("org.apache.commons.httpclient.MultiThreadedHttpConnectionManager".equals(name)) {
                    // Simulate class not found
                    throw new ClassNotFoundException(name);
                }
                return super.loadClass(name);

					<artifactId>geo</artifactId>
				</exclusion>
			</exclusions>
		</dependency>
		<dependency>
			<groupId>org.codelibs.fesen.client</groupId>
			<artifactId>fesen-httpclient</artifactId>
			<version>${fesen.httpclient.version}</version>
		</dependency>
		<dependency>
			<groupId>org.ow2.asm</groupId>
			<artifactId>asm</artifactId>
			<version>${asm.version}</version>
		</dependency>

     * @throws SearchEngineClientException if the client is not an HttpClient
     */
    public EngineInfo getEngineInfo() {
        if (client instanceof final HttpClient httpClient) {
            return httpClient.getEngineInfo();
        }
        throw new SearchEngineClientException("client is not HttpClient.");
    }

    //
    // Fesen Client
    //

    /**

      this.fastFallback = okHttpClient.fastFallback
      this.authenticator = okHttpClient.authenticator
      this.followRedirects = okHttpClient.followRedirects
      this.followSslRedirects = okHttpClient.followSslRedirects
      this.cookieJar = okHttpClient.cookieJar
      this.cache = okHttpClient.cache
      this.dns = okHttpClient.dns
      this.proxy = okHttpClient.proxy
      this.proxySelector = okHttpClient.proxySelector

        if (StringUtil.isNotBlank(proxyHost) && StringUtil.isNotBlank(proxyPort)) {
            factoryParamMap.put(HcHttpClient.PROXY_HOST_PROPERTY, proxyHost);
            factoryParamMap.put(HcHttpClient.PROXY_PORT_PROPERTY, proxyPort);
            final String proxyUsername = paramMap.get(CRAWLER_WEB_PREFIX + "proxyUsername");

            public static final String FTP_AUTHENTICATIONS = FtpClient.FTP_AUTHENTICATIONS_PROPERTY;
            public static final String ROBOTS_TXT_ENABLED = HcHttpClient.ROBOTS_TXT_ENABLED_PROPERTY;
            public static final String PROXY_PASSWORD = "proxyPassword";
            public static final String PROXY_USERNAME = "proxyUsername";
            public static final String PROXY_PORT = HcHttpClient.PROXY_PORT_PROPERTY;

      )
    }
  }

  @Test fun testH2PriorKnowledgeOkHttpClientConstructionSuccess() {
    val okHttpClient =
      OkHttpClient
        .Builder()
        .protocols(listOf(Protocol.H2_PRIOR_KNOWLEDGE))
        .build()
    assertThat(okHttpClient.protocols.size).isEqualTo(1)
    assertThat(okHttpClient.protocols[0]).isEqualTo(Protocol.H2_PRIOR_KNOWLEDGE)
  }

  @Test fun nullDefaultProxySelector() {

	public final fun authenticator (Lokhttp3/Authenticator;)Lokhttp3/OkHttpClient$Builder;
	public final fun build ()Lokhttp3/OkHttpClient;
	public final fun cache (Lokhttp3/Cache;)Lokhttp3/OkHttpClient$Builder;
	public final fun callTimeout (JLjava/util/concurrent/TimeUnit;)Lokhttp3/OkHttpClient$Builder;
	public final fun callTimeout (Ljava/time/Duration;)Lokhttp3/OkHttpClient$Builder;

    ```java
      private final OkHttpClient client = new OkHttpClient();

      public void run() throws Exception {
        Request request = new Request.Builder()
            .url("http://httpbin.org/delay/1") // This URL is served with a 1 second delay.
            .build();

        // Copy to customize OkHttp for this request.
        OkHttpClient client1 = client.newBuilder()

Backwards-Incompatible Changes
------------------------------

#### OkHttpClient final methods

`OkHttpClient` has 26 accessors like `interceptors()` and `writeTimeoutMillis()` that were non-final
in OkHttp 3.x and are final in 4.x. These were made non-final for use with mocking frameworks like
[Mockito][mockito]. We believe subtyping `OkHttpClient` is the wrong way to test with OkHttp. If