import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A {@link RunnableFuture} that also implements the {@link ListenableFuture} interface.
 *
 * <p>This should be used in preference to {@link ListenableFutureTask} when possible for
 * performance reasons.
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault

        // and enclosingclass -> superClass paths.
        // Since we follow the path of superclass first, enclosing second,
        // superclass mapping should take precedence.
        return;
      }
      // First, check whether var -> arg forms a cycle
      for (Type t = arg; t != null; t = mappings.get(TypeVariableKey.forLookup(t))) {
        if (var.equalsType(t)) {

  }

  /**
   * Returns an unmodifiable view of the specified collection, preserving the interface for
   * instances of {@code SortedSet}, {@code Set}, {@code List} and {@code Collection}, in that order
   * of preference.
   *
   * @param collection the collection for which to return an unmodifiable view
   * @return an unmodifiable view of the collection
   */

  }

  private final WeakReference<Class<?>> finalizableReferenceClassReference;
  private final PhantomReference<Object> frqReference;
  private final ReferenceQueue<Object> queue;

  // By preference, we will use the Thread constructor that has an `inheritThreadLocals` parameter.
  // But before Java 9, our only way not to inherit ThreadLocals is to zap them after the thread
  // is created, by accessing a private field.

   * or {@code 'A'} and {@code 'Z'} inclusive.
   *
   * <p>This method is significantly faster than {@link String#equalsIgnoreCase} and should be used
   * in preference if at least one of the parameters is known to contain only ASCII characters.
   *
   * <p>Note however that this method does not always behave identically to expressions such as:
   *
   * <ul>

     *     we're not sure if entry will necessarily ever be garbage collected.
     * @param newNext entry in the same bucket
     * @param key the key to copy from the original entry to the new one. Use this in preference to
     *     {@code original.getKey()}.
     */
    // Guarded By Segment.this
    <K, V> ReferenceEntry<K, V> copyEntry(

  }

  private final WeakReference<Class<?>> finalizableReferenceClassReference;
  private final PhantomReference<Object> frqReference;
  private final ReferenceQueue<Object> queue;

  // By preference, we will use the Thread constructor that has an `inheritThreadLocals` parameter.
  // But before Java 9, our only way not to inherit ThreadLocals is to zap them after the thread
  // is created, by accessing a private field.

   * false}.
   *
   * <p>If you want to filter an {@code Iterable} to narrow its type, consider using {@link
   * com.google.common.collect.Iterables#filter(Iterable, Class)} in preference.
   *
   * <p><b>Warning:</b> contrary to the typical assumptions about predicates (as documented at
   * {@link Predicate#apply}), the returned predicate may not be <i>consistent with equals</i>. For

  /** The HTTP {@code Upgrade} header field name. */
  public static final String UPGRADE = "Upgrade";
  /**
   * The HTTP <a href="https://w3c.github.io/webappsec-upgrade-insecure-requests/#preference">{@code
   * Upgrade-Insecure-Requests}</a> header field name.
   *
   * @since 28.1
   */
  public static final String UPGRADE_INSECURE_REQUESTS = "Upgrade-Insecure-Requests";

 *
 * <ul>
 *   <li>An annotation named just "Suppress" might someday be treated by a non-Android tool as a
 *       suppression. This would follow the precedent of many of our annotation processors, which
 *       look for any annotation named, e.g., "GwtIncompatible," regardless of package.
 *   <li>An annotation named just "Suppress" might suggest to users that the test is suppressed