shares connections when hosts share both IP addresses and certificates, such as `squareup.com`
    and `www.squareup.com`. If a server refuses such sharing it will return HTTP 421 and OkHttp will
    automatically retry on an unshared connection.
 *  Fix: Don't crash if a TLS tunnel's response body is truncated.

    assertThat(response.body.contentType()).isNull()
    assertThat(response.body.contentLength()).isEqualTo(0L)
    assertThat(response.body.byteString()).isEqualTo(EMPTY)
  }

  /**
   * Returns a new response body that refuses to be read once it has been closed. This is true of
   * most [BufferedSource] instances, but not of [Buffer].
   */
  private fun responseBody(content: String): ResponseBody {
    val data = Buffer().writeUtf8(content)

          handshakeCertificates2.sslSocketFactory(),
          handshakeCertificates2.trustManager,
        )
        .build()

    // This client fails to connect because the new SSL socket factory refuses.
    assertFailsWith<IOException> {
      anotherClient.newCall(request).execute()
    }.also { expected ->
      when (expected) {
        is SSLException, is TlsFatalAlert -> {}
        else -> throw expected

    assertThat(server.takeRequest().sequenceNumber).isEqualTo(0)

    // Second CONNECT call needs a new connection.
    assertThat(server.takeRequest().sequenceNumber).isEqualTo(0)

    // GET reuses the connection from the second connect.
    assertThat(server.takeRequest().sequenceNumber).isEqualTo(1)
  }

  @Test
  fun tooManyProxyAuthFailuresWithConnectionClose() {

higher throughput (due to [TCP slow start](https://www.igvita.com/2011/10/20/faster-web-vs-tcp-slow-start/)) and conserved battery. OkHttp uses a [ConnectionPool](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-connection-pool/) that automatically reuses HTTP/1.x connections and multiplexes HTTP/2 connections.

In OkHttp some fields of the address come from the URL (scheme, hostname, port) and the rest come from the [OkHttpClient](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-ok-http-client/)....

 *  Fix: Log plaintext bodies only. This uses simple heuristics to differentiate
    text from other data.
 *  Fix: Recover from `REFUSED_STREAM` errors in HTTP/2. This should improve
    interoperability with Nginx 1.10.0, which [refuses][nginx_959] streams
    created before HTTP/2 settings have been acknowledged.
 *  Fix: Improve recovery from failed routes.
 *  Fix: Accommodate tunneling proxies that close the connection after an auth
    challenge.

    assertThat(server.takeRequest().sequenceNumber).isEqualTo(1) // Pooled connection.
    assertThat(server.takeRequest().sequenceNumber).isEqualTo(0) // New connection.

    // Third call reuses the second connection.
    val response3 = client.newCall(request).execute()
    assertThat(response3.body.string()).isEqualTo("def")
    assertThat(server.takeRequest().sequenceNumber).isEqualTo(1) // New connection.
  }

    assertThat(response.body.string()).isEqualTo("abc")

    assertFailsWith<IllegalStateException> {
      response.peekBody(3)
    }
  }

  /**
   * Returns a new response body that refuses to be read once it has been closed. This is true of
   * most [BufferedSource] instances, but not of [Buffer].
   */
  private fun responseBody(content: String): ResponseBody {
    val data = Buffer().writeUtf8(content)

     *   failure to reach any individual IP address doesn't fail the overall request. This can
     *   increase availability of multi-homed services.
     *
     * * **Stale pooled connections.** The [ConnectionPool] reuses sockets
     *   to decrease request latency, but these connections will occasionally time out.
     *
     * * **Unreachable proxy servers.** A [ProxySelector] can be used to