* ListenableFuture}</a>.
 *
 * <p>This class is GWT-compatible.
 *
 * <h3>Purpose</h3>
 *
 * <p>The main purpose of {@code ListenableFuture} is to help you chain together a graph of
 * asynchronous operations. You can chain them together manually with calls to methods like {@link
 * Futures#transform(ListenableFuture, com.google.common.base.Function, Executor) Futures.transform}

import java.util.concurrent.atomic.AtomicReference;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Serializes execution of tasks, somewhat like an "asynchronous {@code synchronized} block." Each
 * {@linkplain #submit enqueued} callable will not be submitted to its associated executor until the

 * article on <a href="https://github.com/google/guava/wiki/ListenableFutureExplained">{@code
 * ListenableFuture}</a>.
 *
 * <p>The main purpose of {@code ListenableFuture} is to help you chain together a graph of
 * asynchronous operations. You can chain them together manually with calls to methods like {@link
 * Futures#transform(ListenableFuture, Function, Executor) Futures.transform}, but you will often

   * currently contains a value for {@code key}, and {@link CacheLoader#load} otherwise. Loading is
   * asynchronous only if {@link CacheLoader#reload} was overridden with an asynchronous
   * implementation.
   *
   * <p>Returns without doing anything if another thread is currently loading the value for {@code

 * Caffeine}</a> class. Caffeine offers better performance, more features (including asynchronous
 * loading), and fewer <a
 * href="https://github.com/google/guava/issues?q=is%3Aopen+is%3Aissue+label%3Apackage%3Dcache+label%3Atype%3Ddefect">bugs</a>.
 *
 * <p>Caffeine defines its own interfaces (<a

  }

  /**
   * An object that holds the final result of an asynchronous {@link ClosingFuture} operation and
   * allows the user to close all the closeable objects that were captured during it for later
   * closing.
   *
   * <p>The asynchronous operation will have completed before this object is created.
   *
   * @param <V> the type of the value of a successful operation

   * executor}.
   *
   * @param listener the backing listener
   * @param executor the executor with which removal notifications are asynchronously executed
   */
  public static <K, V> RemovalListener<K, V> asynchronous(
      RemovalListener<K, V> listener, Executor executor) {
    checkNotNull(listener);
    checkNotNull(executor);
    return (RemovalNotification<K, V> notification) ->