* natural ordering.
   *
   * <p><b>Note:</b> if mutability is not required, use {@link ImmutableSortedSet#copyOf(Iterable)}
   * instead.
   *
   * <p><b>Note:</b> If {@code elements} is a {@code SortedSet} with an explicit comparator, this
   * method has different behavior than {@link TreeSet#TreeSet(SortedSet)}, which returns a {@code
   * TreeSet} with that comparator.
   *

   * href="https://goo.gl/Y6SLWx">comparison of several definitions of "whitespace"</a>.)
   *
   * <p>All Unicode White_Space characters are on the BMP and thus supported by this API.
   *
   * <p><b>Note:</b> as the Unicode definition evolves, we will modify this matcher to keep it up to
   * date.
   *
   * @since 19.0 (since 1.0 as constant {@code WHITESPACE})
   */
  public static CharMatcher whitespace() {

 *
 * {@code CacheBuilder} builds caches with any combination of the following features:
 *
 * <ul>
 *   <li>automatic loading of entries into the cache
 *   <li>least-recently-used eviction when a maximum size is exceeded (note that the cache is
 *       divided into segments, each of which does LRU internally)
 *   <li>time-based expiration of entries, measured since last access or last write
 *   <li>keys automatically wrapped in {@code WeakReference}

@ReflectionSupport(value = ReflectionSupport.Level.FULL)
@ElementTypesAreNonnullByDefault
public abstract class AbstractFuture<V extends @Nullable Object> extends InternalFutureFailureAccess
    implements ListenableFuture<V> {
  // NOTE: Whenever both tests are cheap and functional, it's faster to use &, | instead of &&, ||

  static final boolean GENERATE_CANCELLATION_CAUSES;

  static {

                    e);
            throw problems.newModelBuilderException();
        } catch (IOException e) {
            String msg = e.getMessage();
            if (msg == null || msg.isEmpty()) {
                // NOTE: There's java.nio.charset.MalformedInputException and sun.io.MalformedInputException
                if (e.getClass().getName().endsWith("MalformedInputException")) {

                        for (PluginExecution execution : plugin.getExecutions()) {
                            if (executionId.equals(execution.getId())) {
                                // NOTE: The PluginConfigurationExpander already merged the plugin-level config in
                                dom = (Xpp3Dom) execution.getConfiguration();
                                break;
                            }

   * number of elements and every element of {@code iterator1} is equal to the corresponding element
   * of {@code iterator2}.
   *
   * <p>Note that this will modify the supplied iterators, since they will have been advanced some
   * number of elements forward.
   */
  public static boolean elementsEqual(Iterator<?> iterator1, Iterator<?> iterator2) {

 * @author Nishant Thakkar
 * @author Sven Mawson
 * @since 1.0
 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public final class Futures extends GwtFuturesCatchingSpecialization {

  // A note on memory visibility.
  // Many of the utilities in this class (transform, withFallback, withTimeout, asList, combine)
  // have two requirements that significantly complicate their design.

      return new ImmutableSortedMap<>(
          ImmutableSortedSet.emptySet(comparator), ImmutableList.<V>of());
    }
  }

  /**
   * Returns the empty sorted map.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */
  @SuppressWarnings("unchecked")
  // unsafe, comparator() returns a comparator on the specified type

    /** Gets the entry's hash. */
    int getHash();

    /** Gets the key for this entry. */
    K getKey();

    /** Gets the value for the entry. */
    V getValue();
  }

  /*
   * Note: the following classes have a lot of duplicate code. It sucks, but it saves a lot of
   * memory. If only Java had mixins!
   */

  /** Base class for {@link InternalEntry} implementations for strong keys. */