*
 * @author James Sexton
 * @author Joshua O'Madadhain
 * @author Omar Darwish
 * @param <N> Node parameter type
 * @param <V> Value parameter type
 */
@ElementTypesAreNonnullByDefault
class StandardValueGraph<N, V> extends AbstractValueGraph<N, V> {
  private final boolean isDirected;
  private final boolean allowsSelfLoops;
  private final ElementOrder<N> nodeOrder;

 * @param <V> Value parameter type
 * @since 20.0
 */
@Beta
@Immutable(containerOf = {"N", "V"})
@SuppressWarnings("Immutable") // Extends StandardValueGraph but uses ImmutableMaps.
@ElementTypesAreNonnullByDefault
public final class ImmutableValueGraph<N, V> extends StandardValueGraph<N, V> {

  private ImmutableValueGraph(ValueGraph<N, V> graph) {
    super(ValueGraphBuilder.from(graph), getNodeConnections(graph), graph.edges().size());

 * @param <V> Value parameter type
 * @since 20.0
 */
@Beta
@Immutable(containerOf = {"N", "V"})
@SuppressWarnings("Immutable") // Extends StandardValueGraph but uses ImmutableMaps.
@ElementTypesAreNonnullByDefault
public final class ImmutableValueGraph<N, V> extends StandardValueGraph<N, V> {

  private ImmutableValueGraph(ValueGraph<N, V> graph) {
    super(ValueGraphBuilder.from(graph), getNodeConnections(graph), graph.edges().size());

  public static <N> ImmutableGraph<N> copyOf(Graph<N> graph) {
    return (graph instanceof ImmutableGraph)
        ? (ImmutableGraph<N>) graph
        : new ImmutableGraph<N>(
            new StandardValueGraph<N, Presence>(
                GraphBuilder.from(graph), getNodeConnections(graph), graph.edges().size()));
  }

  /**
   * Simply returns its argument.
   *
   * @deprecated no need to use this
   */