@Override
        public @Nullable Object apply(Optional<?> optional) {
          return optional.orNull();
        }
      };

  /**
   * Sets.cartesianProduct doesn't allow sets that contain null, but we want null to mean "don't
   * call the associated CacheBuilder method" - that is, get the default CacheBuilder behavior. This

      try {
        Object actualReturnValue = method.invoke(wrapper, passedArgs);
        // If we think this might be a 'chaining' call then we allow the return value to either
        // be the wrapper or the returnValue.
        if (!isPossibleChainingCall || wrapper != actualReturnValue) {
          assertEquals(

      try {
        Object actualReturnValue = method.invoke(wrapper, passedArgs);
        // If we think this might be a 'chaining' call then we allow the return value to either
        // be the wrapper or the returnValue.
        if (!isPossibleChainingCall || wrapper != actualReturnValue) {
          assertEquals(

   * creates a new empty iterator.
   */
  protected AbstractSequentialIterator(@CheckForNull T firstOrNull) {
    this.nextOrNull = firstOrNull;
  }

  /**
   * Returns the element that follows {@code previous}, or returns {@code null} if no elements
   * remain. This method is invoked during each call to {@link #next()} in order to compute the
   * result of a <i>future</i> call to {@code next()}.
   */
  @CheckForNull

 *   <li>the hash codes of any two equal objects are equal
 * </ul>
 *
 * <p>When a test fails, the error message labels the objects involved in the failed comparison as
 * follows:
 *
 * <ul>
 *   <li>"{@code [group }<i>i</i>{@code , item }<i>j</i>{@code ]}" refers to the
 *       <i>j</i><sup>th</sup> item in the <i>i</i><sup>th</sup> equality group, where both equality

    GraphBuilder<N1> castBuilder = cast();
    return new ImmutableGraph.Builder<>(castBuilder);
  }

  /**
   * Specifies whether the graph will allow self-loops (edges that connect a node to itself).
   * Attempting to add a self-loop to a graph that does not allow them will throw an {@link
   * UnsupportedOperationException}.
   *
   * <p>The default value is {@code false}.
   */
  @CanIgnoreReturnValue

   * {@code new ImmutableMapEntry[...]}, so it seems silly to insist on that only here.
   */
  @SuppressWarnings("unchecked") // Safe as long as the javadocs are followed
  static <K, V> ImmutableMapEntry<K, V>[] createEntryArray(int size) {
    return (ImmutableMapEntry<K, V>[]) new ImmutableMapEntry<?, ?>[size];
  }

  ImmutableMapEntry(K key, V value) {
    super(key, value);

   * concurrently updating.
   */
  public void reset() {
    internalReset(0L);
  }

  /**
   * Equivalent in effect to {@link #sum} followed by {@link #reset}. This method may apply for
   * example during quiescent points between multithreaded computations. If there are updates
   * concurrent with this method, the returned value is not guaranteed to be the final

 * ClassToInstanceMap}</a>.
 *
 * @param <B> the common supertype that all values will share. When in doubt, just use {@link
 *     Object}, or use {@code @Nullable Object} to allow null values.
 * @since 2.0
 */
@DoNotMock("Use ImmutableClassToInstanceMap or MutableClassToInstanceMap")
@GwtCompatible
@ElementTypesAreNonnullByDefault
public interface ClassToInstanceMap<B extends @Nullable Object>

import java.util.Set;
import javax.annotation.CheckForNull;

/**
 * An empty contiguous set.
 *
 * @author Gregory Kick
 */
@GwtCompatible(emulated = true)
@SuppressWarnings("rawtypes") // allow ungenerified Comparable types
@ElementTypesAreNonnullByDefault
final class EmptyContiguousSet<C extends Comparable> extends ContiguousSet<C> {
  EmptyContiguousSet(DiscreteDomain<C> domain) {
    super(domain);
  }