*
 * Percent encoding is used in every URL component except for the hostname. But the set of
 * characters that need to be encoded is different for each component. For example, the path
 * component must escape all of its `?` characters, otherwise it could be interpreted as the
 * start of the URL's query. But within the query and fragment components, the `?` character
 * doesn't delimit anything and doesn't need to be escaped.
 *

          parse(
            responseHeaders,
          ),
          RealWebSocket.DEFAULT_MINIMUM_DEFLATE_SIZE,
          webSocketCloseTimeout,
        ).apply {
          if (client) {
            call =
              object : FailingCall() {
                override fun cancel() {
                  ******@****.***()
                }
              }
          }
        }

  integrity sha512-/Nf7TyzTx6S3yRJObOAV7956r8cr2+Oj8AC5dt8wSP3BQAoeX58NoHyCU8P8zGkNXStjTSi6fzO6F0pBdcYbEg==

call-bind@^1.0.0:
  version "1.0.2"
  resolved "https://registry.yarnpkg.com/call-bind/-/call-bind-1.0.2.tgz#b1d4e89e688119c3c9a903ad30abb2f6a919be3c"
  integrity sha512-7O+FbCihrB5WGbFYesctwmTKae6rOiIzmz1icreWJ+0aA7LJfuqhEso2T9ncpcFtzMQtzXf2QGGueWJGTYsqrA==
  dependencies:

      assertThat(queueSize).isBetween(0L, messageCount * message.size)
      // Expect to fail before enqueueing 32 MiB.
      assertThat(messageCount).isLessThan(32L)
    }

    // Confirm all sent messages were received, followed by a client-initiated close.
    val server = serverListener.assertOpen()
    for (i in 0 until messageCount) {
      serverListener.assertBinaryMessage(message)
    }

    server.requestClientAuth()
    server.enqueue(
      MockResponse.Builder()
        .body("abc")
        .build(),
    )
    val call = client.newCall(Request.Builder().url(server.url("/")).build())
    val response = call.execute()
    assertThat(response.handshake!!.peerPrincipal)
      .isEqualTo(X500Principal("CN=Local Host"))
    assertThat(response.handshake!!.localPrincipal)

 * **ExchangeFinder** chooses which connection carries each exchange. Where possible it will use the same connection for all exchanges in a single call. It prefers reusing pooled connections over establishing new connections.      

#### Per-Connection Locks

    var retryTlsConnection: ConnectPlan? = null
    var success = false

    // Tell the call about the connecting call so async cancels work.
    user.addPlanToCancel(this)
    try {
      if (tunnelRequest != null) {
        val tunnelResult = connectTunnel()

        // Tunnel didn't work. Start it all again.
        if (tunnelResult.nextPlan != null || tunnelResult.throwable != null) {
          return tunnelResult

     */
    open fun addHeader(
      name: String,
      value: String,
    ) = commonAddHeader(name, value)

    /** Removes all headers named [name] on this builder. */
    open fun removeHeader(name: String) = commonRemoveHeader(name)

    /** Removes all headers on this builder and adds [headers]. */
    open fun headers(headers: Headers) = commonHeaders(headers)

    val request = Request(server.url("/a"))
    val call = client.newCall(request)
    call.enqueue(
      object : Callback {
        override fun onFailure(
          call: Call,
          e: IOException,
        ) {
          failureRef.set(true)
          latch.countDown()
        }

        override fun onResponse(
          call: Call,
          response: Response,
        ) {

   * mutated by the call thread only. If is accessed by background connect threads.
   */
  private val tcpConnectsInFlight = CopyOnWriteArrayList<Plan>()

  /**
   * Results are posted here as they occur. The find job is done when either one plan completes
   * successfully or all plans fail.
   */