listOf(
        localhostIpv4,
        localhostIpv6,
        TestUtil.UNREACHABLE_ADDRESS_IPV4.address,
      )
    serverIpv4.protocols = listOf(Protocol.H2_PRIOR_KNOWLEDGE)
    serverIpv6.protocols = listOf(Protocol.H2_PRIOR_KNOWLEDGE)

    // Yield the first IP address so the second IP address completes first.
    val firstConnectLatch = CountDownLatch(1)
    val socketFactory =

      server.protocols = listOf(Protocol.H2_PRIOR_KNOWLEDGE, Protocol.H2_PRIOR_KNOWLEDGE)
      fail<Any>()
    } catch (expected: IllegalArgumentException) {
      assertThat(expected.message).isEqualTo(
        "protocols containing h2_prior_knowledge cannot use other protocols: " +
          "[h2_prior_knowledge, h2_prior_knowledge]",
      )
    }
  }

  @Test

      server.protocols = listOf(Protocol.H2_PRIOR_KNOWLEDGE, Protocol.H2_PRIOR_KNOWLEDGE)
      fail<Unit>()
    } catch (expected: IllegalArgumentException) {
      assertThat(expected.message).isEqualTo(
        "protocols containing h2_prior_knowledge cannot use other protocols: " +
          "[h2_prior_knowledge, h2_prior_knowledge]",
      )
    }
  }

  @Test

    set(value) {
      val protocolList = value.toImmutableList()
      require(Protocol.H2_PRIOR_KNOWLEDGE !in protocolList || protocolList.size == 1) {
        "protocols containing h2_prior_knowledge cannot use other protocols: $protocolList"
      }
      require(Protocol.HTTP_1_1 in protocolList || Protocol.H2_PRIOR_KNOWLEDGE in protocolList) {
        "protocols doesn't contain http/1.1: $protocolList"
      }

  private val http2Connection: Http2Connection,
) : ExchangeCodec {
  @Volatile private var stream: Http2Stream? = null

  private val protocol: Protocol =
    if (Protocol.H2_PRIOR_KNOWLEDGE in client.protocols) {
      Protocol.H2_PRIOR_KNOWLEDGE
    } else {
      Protocol.HTTP_2
    }

  @Volatile
  private var canceled = false

  override val isResponseComplete: Boolean
    get() = stream?.isSourceComplete == true

        call.eventListener.secureConnectEnd(call, handshake)
      } else {
        javaNetSocket = rawSocket
        protocol =
          when {
            Protocol.H2_PRIOR_KNOWLEDGE in route.address.protocols -> Protocol.H2_PRIOR_KNOWLEDGE
            else -> Protocol.HTTP_1_1
          }
      }

      val connection =
        RealConnection(
          taskRunner = taskRunner,

          "CLEARTEXT communication to $host not permitted by network security policy",
        )
      }
    } else {
      if (Protocol.H2_PRIOR_KNOWLEDGE in route.address.protocols) {
        throw UnknownServiceException("H2_PRIOR_KNOWLEDGE cannot be used with HTTPS")
      }
    }

    val tunnelRequest =
      when {
        route.requiresTunnel() -> createTunnelRequest(route)

        require(Protocol.H2_PRIOR_KNOWLEDGE in protocolsCopy || HTTP_1_1 in protocolsCopy) {
          "protocols must contain h2_prior_knowledge or http/1.1: $protocolsCopy"
        }
        require(Protocol.H2_PRIOR_KNOWLEDGE !in protocolsCopy || protocolsCopy.size <= 1) {
          "protocols containing h2_prior_knowledge cannot use other protocols: $protocolsCopy"
        }

    withLock {
      successCount++
    }
  }

  @Throws(IOException::class)
  fun start() {
    idleAtNs = System.nanoTime()
    if (protocol == Protocol.HTTP_2 || protocol == Protocol.H2_PRIOR_KNOWLEDGE) {
      startHttp2()
    }
  }

  @Throws(IOException::class)
  private fun startHttp2() {
    javaNetSocket.soTimeout = 0 // HTTP/2 connection timeouts are set per-stream.

          .build()
      scheme = "https"
    } else {
      server.protocols = listOf(Protocol.H2_PRIOR_KNOWLEDGE)
      client =
        clientTestRule
          .newClientBuilder()
          .protocols(listOf(Protocol.H2_PRIOR_KNOWLEDGE))
          .build()
      scheme = "http"
    }
  }

  @AfterEach fun tearDown() {