*/
    protected static final String OPTIONS = "OPTIONS";

    @Override
    public void doFilter(final ServletRequest request, final ServletResponse response, final FilterChain chain)
            throws IOException, ServletException {
        final HttpServletRequest httpRequest = (HttpServletRequest) request;
        final String origin = httpRequest.getHeader("Origin");

            @Override
            public QueryBuilder execute(QueryContext context, Query query, float boost, FilterChain chain) {
                calledFirst.set(true);
                assertFalse(called.get());
                QueryBuilder builder = chain.execute(context, query, boost);
                assertTrue(called.get());
                return builder;
            }
        });

          connectionPool = connectionPool,
          readTimeoutMillis = client.readTimeoutMillis,
          writeTimeoutMillis = client.writeTimeoutMillis,
          socketConnectTimeoutMillis = chain.connectTimeoutMillis,
          socketReadTimeoutMillis = chain.readTimeoutMillis,
          pingIntervalMillis = client.pingIntervalMillis,
          retryOnConnectionFailure = client.retryOnConnectionFailure,
          fastFallback = client.fastFallback,

  }

  @Test
  fun interceptor() {
    var interceptor: Interceptor = Interceptor { TODO() }
    interceptor = Interceptor { it: Interceptor.Chain -> TODO() }
  }

  @Test
  fun interceptorChain() {
    val chain: Interceptor.Chain = newInterceptorChain()
  }

  @Test
  fun handshakeCertificates() {
    val handshakeCertificates = HandshakeCertificates.Builder().build()

  }

  /**
   * Gets a {@code Throwable} cause chain as a list. The first entry in the list will be {@code
   * throwable} followed by its cause hierarchy. Note that this is a snapshot of the cause chain and
   * will not reflect any subsequent changes to the cause chain.
   *
   * <p>Here's an example of how it can be used to find specific types of exceptions in the cause
   * chain:
   *
   * <pre>

     * @param request The HTTP servlet request.
     * @param response The HTTP servlet response.
     * @param chain The filter chain.
     * @throws IOException If an input/output error occurs.
     * @throws ServletException If a servlet error occurs.
     */
    void process(HttpServletRequest request, HttpServletResponse response, FilterChain chain) throws IOException, ServletException;

        }
    }

    @Nested
    @DisplayName("Chain Tests")
    class ChainTests {

        @Test
        @DisplayName("Should chain messages successfully")
        void testChain() {
            TestServerMessageBlock2 nextMessage = new TestServerMessageBlock2(mockConfig);
            assertTrue(testMessage.chain(nextMessage));
            assertEquals(nextMessage, testMessage.getNext());

OdHOim9+
-----END PRIVATE KEY-----
```

Recommendations
---------------

Typically servers need a held certificate plus a chain of intermediates. Servers only need the
private key for their own certificate. The chain served by a server doesn't need the root
certificate.

The trusted roots don't need to be the same for client and server when using client authentication.

    var connection: RealConnection? = null
    client =
      client
        .newBuilder()
        .addNetworkInterceptor(
          Interceptor { chain ->
            connection = chain.connection() as RealConnection
            chain.proceed(chain.request())
          },
        ).build()

    server.enqueue(
      MockResponse
        .Builder()
        .body("a")
        .onResponseEnd(

/**
 * A connection user that is a specific [RealCall].
 */
internal class CallConnectionUser(
  private val call: RealCall,
  private val poolConnectionListener: ConnectionListener,
  private val chain: RealInterceptorChain,
) : ConnectionUser {
  private val eventListener: EventListener
    get() = call.eventListener

  override fun addPlanToCancel(connectPlan: ConnectPlan) {
    call.plansToCancel += connectPlan