FailedPlan(e)
          }
        }
        else -> return null // Nothing further to try.
      }

    // Already connected. Return it immediately.
    if (plan.isReady) return ConnectResult(plan)

    // Already failed? Return it immediately.
    if (plan is FailedPlan) return plan.result

    // Connect TCP asynchronously.
    tcpConnectsInFlight += plan

   * exception.
   *
   * @throws IllegalStateException when the call has already been executed.
   */
  fun enqueue(responseCallback: Callback)

  /** Cancels the request, if possible. Requests that are already complete cannot be canceled. */
  fun cancel()

  /**
   * Returns true if this call has been either [executed][execute] or [enqueued][enqueue]. It is an

/** Reuse a connection from the pool. */
internal class ReusePlan(
  val connection: RealConnection,
) : RoutePlanner.Plan {
  override val isReady = true

  override fun connectTcp() = error("already connected")

  override fun connectTlsEtc() = error("already connected")

  override fun handleSuccess() = connection

  override fun cancel() = error("unexpected cancel")

   * be transmitted before the close message is sent but subsequent calls to [send] will return
   * false and their messages will not be enqueued.
   *
   * This returns true if a graceful shutdown was initiated by this call. It returns false if
   * a graceful shutdown was already underway or if the web socket is already closed or canceled.
   *

        return map.containsKey(o);
    }

    /**
     * Adds the specified element to this set if it is not already present.
     *
     * @param o
     *            element to be added to this set.
     * @return true if the set did not already contain the specified
     *         element.
     */
    @Override
    public boolean add(final E o) {

   * @throws IllegalStateException if a maximum size or weight was already set
   */
  @CanIgnoreReturnValue
  public CacheBuilder<K, V> maximumSize(long maximumSize) {
    checkState(
        this.maximumSize == UNSET_INT, "maximum size was already set to %s", this.maximumSize);
    checkState(
        this.maximumWeight == UNSET_INT,
        "maximum weight was already set to %s",
        this.maximumWeight);

   * already been determined.
   */
  public abstract <T extends @Nullable Object> ComparisonChain compare(
      @ParametricNullness T left, @ParametricNullness T right, Comparator<T> comparator);

  /**
   * Compares two {@code int} values as specified by {@link Integer#compare}, <i>if</i> the result
   * of this comparison chain has not already been determined.
   */

     *
     * @param body the body content
     * @return this CurlRequest instance
     * @throws CurlException if the body method is already called
     */
    public CurlRequest body(final String body) {
        if (bodyStream != null) {
            throw new CurlException("body method is already called.");
        }
        this.body = body;
        return this;
    }

    /**

   * uninterruptibly.
   *
   * @since 33.4.0 (but since 28.0 in the JRE flavor)
   */
  @J2ktIncompatible
  @GwtIncompatible // concurrency
  @IgnoreJRERequirement // Users will use this only if they're already using Duration.
  public static boolean awaitUninterruptibly(CountDownLatch latch, Duration timeout) {
    return awaitUninterruptibly(latch, toNanosSaturated(timeout), TimeUnit.NANOSECONDS);
  }

  /**

  /**
   * Adds {@code node} if it is not already present.
   *
   * <p><b>Nodes must be unique</b>, just as {@code Map} keys must be. They must also be non-null.
   *
   * @return {@code true} if the graph was modified as a result of this call
   */
  @CanIgnoreReturnValue
  boolean addNode(N node);

  /**
   * Adds an edge connecting {@code nodeU} to {@code nodeV} if one is not already present, and sets