private fun startNextTask(): SerialTask? {
    taskRunner.assertLockHeld()

    val index = serialTaskQueue.indexOfFirst { it.isReady() }
    if (index == -1) return null

    val nextTask = serialTaskQueue.removeAt(index)
    currentTask = nextTask
    contextSwitchCount++
    nextTask.start()
    return nextTask
  }

  private interface SerialTask {
    /** Returns true if this task is ready to start. */

   * 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)

    // Move everything from bytesOut into a new buffer.
    val fullBuffer = Buffer()
    bytesOut.read(fullBuffer, bytesOut.size)

     * to ["a", "b", ""].
     */
    private fun pop() {
      val removed = encodedPathSegments.removeAt(encodedPathSegments.size - 1)

      // Make sure the path ends with a '/' by either adding an empty string or clearing a segment.
      if (removed.isEmpty() && encodedPathSegments.isNotEmpty()) {
        encodedPathSegments[encodedPathSegments.size - 1] = ""
      } else {

      },
    )
  }

  /**
   * Holding the lock of the connection being added or removed when mutating this, and check its
   * [RealConnection.noNewExchanges] property. This defends against races where a connection is
   * simultaneously adopted and removed.
   */
  private val connections = ConcurrentLinkedQueue<RealConnection>()

  init {

    val calls = connection.calls
    val index = calls.indexOfFirst { it.get() == this@RealCall }
    check(index != -1)

    calls.removeAt(index)
    this.connection = null

    if (calls.isEmpty()) {
      connection.idleAtNs = System.nanoTime()
      if (connectionPool.connectionBecameIdle(connection)) {
        return connection.socket()
      }
    }

    return null
  }

    PushObserver,
    Lockable {
    val events = mutableListOf<Any>()

    @Synchronized fun takeEvent(): Any {
      while (events.isEmpty()) {
        wait()
      }
      return events.removeAt(0)
    }

    @Synchronized override fun onRequest(
      streamId: Int,
      requestHeaders: List<Header>,
    ): Boolean {
      assertThat(streamId).isEqualTo(2)

   * removeFrom.removeIf(predicate)} instead.
   *
   * @param removeFrom the iterable to (potentially) remove elements from
   * @param predicate a predicate that determines whether an element should be removed
   * @return {@code true} if any elements were removed from the iterable
   * @throws UnsupportedOperationException if the iterable does not support {@code remove()}.
   * @since 2.0
   */

    }

    /**
     * Removes the specified element from this set if it is present.
     *
     * @param o
     *            object to be removed from this set, if present.
     * @return true if the set contained the specified element.
     */
    @Override
    public boolean remove(final Object o) {
        return map.remove(o) == PRESENT;
    }

    /**

   * otherwise, this method returns false.
   */
  boolean remove(K key, long value) {
    return map.remove(key, value);
  }

  /**
   * Atomically remove {@code key} from the map iff its associated value is 0.
   *
   * @since 20.0
   */
  @CanIgnoreReturnValue
  public boolean removeIfZero(K key) {
    return remove(key, 0);
  }

  /**

     * the URL queue for the current thread is removed.
     *
     * @param urlQueue the URL queue to be set for the current thread, or null to remove the URL queue
     */
    public static void setUrlQueue(final UrlQueue<?> urlQueue) {
        if (urlQueue == null) {
            URL_QUEUE_THREAD_LOCAL.remove();
        } else {
            URL_QUEUE_THREAD_LOCAL.set(urlQueue);
        }
    }