* multimap.
 *
 * <p>The collections returned by {@code keySet}, {@code keys}, and {@code asMap} iterate through
 * the keys in the order they were first added to the multimap. Similarly, {@code get}, {@code
 * removeAll}, and {@code replaceValues} return collections that iterate through the values in the

   */
  public static <K, V> Builder<K, V> builder() {
    return new Builder<>();
  }

  /**
   * Returns a new builder, expecting the specified number of entries to be added.
   *
   * <p>If {@code expectedSize} is exactly the number of entries added to the builder before {@link
   * Builder#build} is called, the builder is likely to perform better than an unsized {@link
   * #builder()} would have.
   *

 * that every {@code Runnable} that is {@linkplain #add added} will be executed after {@link
 * #execute()} is called. Any {@code Runnable} added after the call to {@code execute} is still
 * guaranteed to execute. There is no guarantee, however, that listeners will be executed in the
 * order that they are added.
 *
 * <p>Exceptions thrown by a listener will be propagated up to the executor. Any exception thrown

 * the order they were first added to the multimap. Similarly, {@link #get}, {@link #removeAll}, and
 * {@link #replaceValues} return collections that iterate through the values in the order they were
 * added. The collections generated by {@link #entries()}, {@link #keys()}, and {@link #values}
 * iterate across the key-value mappings in the order they were added to the multimap.
 *

/**
 * Static utilities for {@link InternalFutureFailureAccess}. Most users will never need to use this
 * class.
 *
 * <p>This class is GWT-compatible.
 *
 * @since {@code com.google.guava:failureaccess:1.0}, which was added as a dependency of Guava in
 *     Guava 27.0
 */
public final class InternalFutures {
  /**
   * Usually returns {@code null} but, if the given {@code Future} has failed, may <i>optionally</i>

   * </ul>
   *
   * <p>Note that {@code StandardSystemProperty} does not provide constants for more recently added
   * properties, including:
   *
   * <ul>
   *   <li>{@code java.vendor.version} (added in Java 11, listed as optional as of Java 13)
   *   <li>{@code jdk.module.*} (added in Java 9, optional)
   * </ul>
   */
  @CheckForNull
  public String value() {
    return System.getProperty(key);

 * equivalent elements are added to it, it is undefined which will come first in the output.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
final class TopKSelector<
    T extends @Nullable Object> {

  /**
   * Returns a {@code TopKSelector} that collects the lowest {@code k} elements added to it,

  int getHash();

  /** Returns the key for this entry. */
  @CheckForNull
  K getKey();

  /*
   * Used by entries that use access order. Access entries are maintained in a doubly-linked list.
   * New entries are added at the tail of the list at write time; stale entries are expired from
   * the head of the list.
   */

  /** Returns the time that this entry was last accessed, in ns. */
  @SuppressWarnings("GoodTime")

   * multiple threads can concurrently load values for distinct keys.
   *
   * <p>Caches loaded by a {@link CacheLoader} will call {@link CacheLoader#load} to load new values
   * into the cache. Newly loaded values are added to the cache using {@code
   * Cache.asMap().putIfAbsent} after loading has completed; if another value was associated with
   * {@code key} while the new value was loading then a removal notification will be sent for the

    latch.countDown();

    exec.shutdown();
    exec.awaitTermination(100, MILLISECONDS);
  }

  /**
   * Tests that all listeners complete, even if they were added before or after the future was
   * finishing. Also acts as a concurrency test to make sure the locking is done correctly when a
   * future is finishing so that no listeners can be lost.
   */