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

 * 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);
  }

  private final BaseGraph<N> graph;
  private final Iterator<N> nodeIterator;

  @CheckForNull
  N node = null; // null is safe as an initial value because graphs don't allow null nodes

  Iterator<N> successorIterator = ImmutableSet.<N>of().iterator();

  static <N> EndpointPairIterator<N> of(BaseGraph<N> graph) {
    return graph.isDirected() ? new Directed<N>(graph) : new Undirected<N>(graph);

          } else if (outputFuture.isCancelled() && taskExecutor.trySetCancelled()) {
            // If this CAS succeeds, we know that the provided callable will never be invoked,
            // so when oldFuture completes it is safe to allow the next submitted task to
            // proceed. Doing this immediately here lets the next task run without waiting for
            // the cancelled task's executor to run the noop AsyncCallable.
            //

    assertEquals("null [5, 6]", Strings.lenientFormat(null, 5, 6));
    assertEquals("null", Strings.lenientFormat("%s", (Object) null));
  }

  @J2ktIncompatible // TODO(b/319404022): Allow passing null array as varargs
  public void testLenientFormat_nullArrayVarargs() {
    assertEquals("(Object[])null", Strings.lenientFormat("%s", (Object[]) null));
  }

  /**
   * Returns the escaped form of a given literal string, starting at the given index. This method is
   * called by the {@link #escape(String)} method when it discovers that escaping is required. It is
   * protected to allow subclasses to override the fastpath escaping function to inline their
   * escaping test. See {@link CharEscaperBuilder} for an example usage.
   *

   *
   * <p>The multimap is not threadsafe when any concurrent operations update the multimap, even if
   * {@code map} and the instances generated by {@code factory} are. Concurrent read operations will
   * work correctly. To allow concurrent update operations, wrap the multimap with a call to {@link
   * #synchronizedMultimap}.
   *
   * <p>Call this method only when the simpler methods {@link ArrayListMultimap#create()}, {@link

    if (DASH_MATCHER.matches(part.charAt(0))
        || DASH_MATCHER.matches(part.charAt(part.length() - 1))) {
      return false;
    }

    /*
     * Note that we allow (in contravention of a strict interpretation of the relevant RFCs) domain
     * parts other than the last may begin with a digit (for example, "3com.com"). It's important to

   * strong values, and no automatic eviction of any kind.
   *
   * <p>Note that while this return type is {@code CacheBuilder<Object, Object>}, type parameters on
   * the {@link #build} methods allow you to create a cache of any key and value type desired.
   */
  public static CacheBuilder<Object, Object> newBuilder() {
    return new CacheBuilder<>();
  }

  /**