this.isDirected = builder.directed;
    this.allowsSelfLoops = builder.allowsSelfLoops;
    this.nodeOrder = builder.nodeOrder.cast();
    // Prefer the heavier "MapRetrievalCache" for nodes if lookup is expensive.
    this.nodeConnections =
        (nodeConnections instanceof TreeMap)
            ? new MapRetrievalCache<N, GraphConnections<N, V>>(nodeConnections)

   * [logCloseableLeak].
   */
  open fun getStackTraceForCloseable(closer: String): Any? {
    return when {
      logger.isLoggable(Level.FINE) -> Throwable(closer) // These are expensive to allocate.
      else -> null
    }
  }

  open fun logCloseableLeak(
    message: String,
    stackTrace: Any?,
  ) {
    var logMessage = message
    if (stackTrace == null) {

 *
 * <p>Occasionally, an API will return a plain {@code Future} and it will be impossible to change
 * the return type. For this case, we provide a more expensive workaround in {@code
 * JdkFutureAdapters}. However, when possible, it is more efficient and reliable to create a {@code
 * ListenableFuture} directly.
 *
 * @author Sven Mawson
 * @author Nishant Thakkar

 *
 * <p>Occasionally, an API will return a plain {@code Future} and it will be impossible to change
 * the return type. For this case, we provide a more expensive workaround in {@code
 * JdkFutureAdapters}. However, when possible, it is more efficient and reliable to create a {@code
 * ListenableFuture} directly.
 *
 * @author Sven Mawson
 * @author Nishant Thakkar

 *
 * <p>Occasionally, an API will return a plain {@code Future} and it will be impossible to change
 * the return type. For this case, we provide a more expensive workaround in {@code
 * JdkFutureAdapters}. However, when possible, it is more efficient and reliable to create a {@code
 * ListenableFuture} directly.
 *
 * @author Sven Mawson
 * @author Nishant Thakkar

Let's start with an example and then see it in detail.

We create an async function `lifespan()` with `yield` like this:

{* ../../docs_src/events/tutorial003.py hl[16,19] *}

  }

  /**
   * Returns a larger power of 2 hashtable size given the current mask.
   *
   * <p>For hashtable sizes less than or equal to 32, the returned power of 2 is 4x the current
   * hashtable size to reduce expensive rehashing. Otherwise the returned power of 2 is 2x the
   * current hashtable size.
   */
  static int newCapacity(int mask) {
    return ((mask < 32) ? 4 : 2) * (mask + 1);
  }

       * consistency with how weak references are cleared). That's a behavior change -- arguably the
       * removal of a feature.
       *
       * Fortunately, exceptions rarely contain references to expensive resources.
       */

      //
      seenExceptionsLocal = newConcurrentHashSet();
      /*
       * Other handleException() callers may see this as soon as we publish it. We need to populate

 * of the <i>next</i> request. I.e., if an expensive task arrives at an idle RateLimiter, it will be
 * granted immediately, but it is the <i>next</i> request that will experience extra throttling,
 * thus paying for the cost of the expensive task.
 *
 * @author Dimitris Andreou
 * @since 13.0
 */

Blocking APIs may be inefficient because you hold a thread idle while waiting on the network. Threads are expensive because they have both a memory overhead and a context-switching overhead.

#### Framed protocols