if (executorService.isShutdown) {
      for (i in 0 until executableCalls.size) {
        val asyncCall = executableCalls[i]
        asyncCall.callsPerHost.decrementAndGet()

        synchronized(this) {
          runningAsyncCalls.remove(asyncCall)
        }

        asyncCall.failRejected()
      }
      idleCallback?.run()
    } else {
      for (i in 0 until executableCalls.size) {

 * When making TLS connections with multiple [connection specs](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-connection-spec/), these are attempted in sequence until the TLS handshake succeeds.

### [Connections](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-connection/)

When you request a URL with OkHttp, here's what it does:

    buf.readShort() // authority record count
    buf.readShort() // additional record count

    for (i in 0 until questionCount) {
      skipName(buf) // name
      buf.readShort() // type
      buf.readShort() // class
    }

    for (i in 0 until answerCount) {
      skipName(buf) // name

      val type = buf.readShort().toInt() and 0xffff
      buf.readShort() // class

        }
        requestMethod = source.readUtf8LineStrict()
        val varyHeadersBuilder = Headers.Builder()
        val varyRequestHeaderLineCount = readInt(source)
        for (i in 0 until varyRequestHeaderLineCount) {
          varyHeadersBuilder.addLenient(source.readUtf8LineStrict())
        }
        varyHeaders = varyHeadersBuilder.build()

    var wildcardMatch: String? = null
    if (domainLabelsUtf8Bytes.size > 1) {
      val labelsWithWildcard = domainLabelsUtf8Bytes.clone()
      for (labelIndex in 0 until labelsWithWildcard.size - 1) {
        labelsWithWildcard[labelIndex] = WILDCARD_LABEL
        val rule = publicSuffixList.bytes.binarySearch(labelsWithWildcard, labelIndex)
        if (rule != null) {

    // TODO(user): Consider scaling by number of mutator threads,
    // e.g. using Thread#activeCount()
    return max(10L, Runtime.getRuntime().totalMemory() / (32L * 1024L * 1024L));
  }

  /**
   * Waits until the given future {@linkplain Future#isDone is done}, invoking the garbage collector
   * as necessary to try to ensure that this will happen.
   *
   * @throws RuntimeException if timed out or interrupted while waiting
   */

    return writer
  }

  /**
   * Shortens the last frame from its original length to `length`. This will cause the peer to
   * close the socket as soon as this frame has been written; otherwise the peer stays open until
   * explicitly closed.
   */
  fun truncateLastFrame(length: Int): Http2Writer {
    val lastFrame = outFrames.removeAt(outFrames.size - 1)
    require(length < bytesOut.size - lastFrame.start)

            if (headers["Content-Length"] == null) {
              logger.log("Content-Length: ${requestBody.contentLength()}")
            }
          }
        }

        for (i in 0 until headers.size) {
          logHeader(headers, i)
        }

        if (!logBody || requestBody == null) {
          logger.log("--> END ${request.method}")

  /**
   * Returns a fluent iterable that combines two iterables. The returned iterable has an iterator
   * that traverses the elements in {@code a}, followed by the elements in {@code b}. The source
   * iterators are not polled until necessary.
   *
   * <p>The returned iterable's iterator supports {@code remove()} when the corresponding input
   * iterator supports it.
   *
   * <p><b>{@code Stream} equivalent:</b> {@link Stream#concat}.
   *

  /**
   * Returns a fluent iterable that combines two iterables. The returned iterable has an iterator
   * that traverses the elements in {@code a}, followed by the elements in {@code b}. The source
   * iterators are not polled until necessary.
   *
   * <p>The returned iterable's iterator supports {@code remove()} when the corresponding input
   * iterator supports it.
   *
   * <p><b>{@code Stream} equivalent:</b> {@link Stream#concat}.
   *