protected void afterDone() {}

  // TODO(b/114236866): Inherit doc from InternalFutureFailureAccess. Also, -link to its URL.
  /**
   * Usually returns {@code null} but, if this {@code Future} has failed, may <i>optionally</i>
   * return the cause of the failure. "Failure" means specifically "completed with an exception"; it
   * does not include "was cancelled." To be explicit: If this method returns a non-null value,
   * then:
   *

   *
   * <p><b>Comparison to {@code java.util.Optional}:</b> this method has no equivalent in Java 8's
   * {@code Optional} class; use {@code
   * optionals.stream().filter(Optional::isPresent).map(Optional::get)} instead.
   *
   * <p><b>Java 9 users:</b> use {@code optionals.stream().flatMap(Optional::stream)} instead.
   *
   * @since 11.0 (generics widened in 13.0)
   */
  public static <T> Iterable<T> presentInstances(

            </Export-Package>
            <Import-Package>
              com.google.common.util.concurrent.internal,
              javax.annotation;resolution:=optional,
              javax.crypto.*;resolution:=optional,
              sun.misc.*;resolution:=optional
            </Import-Package>
            <Bundle-DocURL>https://github.com/google/guava/</Bundle-DocURL>
          </instructions>
        </configuration>

  }

  // common.base
  @Empty
  <T> com.google.common.base.Optional<T> generateGoogleOptional() {
    return com.google.common.base.Optional.absent();
  }

  @Generates
  <T> com.google.common.base.Optional<T> generateGoogleOptional(T value) {
    return com.google.common.base.Optional.of(value);
  }

  @Generates
  Joiner generateJoiner() {

import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * CompactLinkedHashMap is an implementation of a Map with insertion or LRU iteration order,
 * maintained with a doubly linked list through the entries. All optional operations (put and
 * remove) are supported. Null keys and values are supported.
 *
 * <p>{@code containsKey(k)}, {@code put(k, v)} and {@code remove(k)} are all (expected and

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.base.Function;
import com.google.common.base.Optional;
import com.google.common.base.Predicate;
import com.google.common.base.Predicates;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.Collection;
import java.util.Comparator;

   *
   * <p><b>Comparison to {@code java.util.Optional}:</b> this method has no equivalent in Java 8's
   * {@code Optional} class; use {@code
   * optionals.stream().filter(Optional::isPresent).map(Optional::get)} instead.
   *
   * <p><b>Java 9 users:</b> use {@code optionals.stream().flatMap(Optional::stream)} instead.
   *
   * @since 11.0 (generics widened in 13.0)
   */
  public static <T> Iterable<T> presentInstances(

 * existing key-value pair, the {@code ArrayListMultimap} will contain entries for both the new
 * value and the old value.
 *
 * <p>Keys and values may be null. All optional multimap methods are supported, and all returned
 * views are modifiable.
 *
 * <p>The lists returned by {@link #get}, {@link #removeAll}, and {@link #replaceValues} all
 * implement {@link java.util.RandomAccess}.
 *

 * existing key-value pair has no effect.
 *
 * <p>Null keys and values are permitted (provided, of course, that the respective comparators
 * support them). All optional multimap methods are supported, and all returned views are
 * modifiable.
 *
 * <p>This class is not threadsafe when any concurrent operations update the multimap. Concurrent

 *
 * <p>By default, {@code BaseEncoding}'s behavior is relatively strict and in accordance with RFC
 * 4648. Decoding rejects characters in the wrong case, though padding is optional. To modify
 * encoding and decoding behavior, use configuration methods to obtain a new encoding with modified
 * behavior:
 *
 * <pre>{@code
 * BaseEncoding.base16().lowerCase().decode("deadbeef");
 * }</pre>
 *