*
 * @author James Sexton
 * @author Joshua O'Madadhain
 * @author Omar Darwish
 * @param <N> Node parameter type
 * @param <E> Edge parameter type
 */
@ElementTypesAreNonnullByDefault
class StandardNetwork<N, E> extends AbstractNetwork<N, E> {
  private final boolean isDirected;
  private final boolean allowsParallelEdges;
  private final boolean allowsSelfLoops;
  private final ElementOrder<N> nodeOrder;

 *
 * @author James Sexton
 * @author Joshua O'Madadhain
 * @author Omar Darwish
 * @param <N> Node parameter type
 * @param <E> Edge parameter type
 */
@ElementTypesAreNonnullByDefault
class StandardNetwork<N, E> extends AbstractNetwork<N, E> {
  private final boolean isDirected;
  private final boolean allowsParallelEdges;
  private final boolean allowsSelfLoops;
  private final ElementOrder<N> nodeOrder;

 * @author Joshua O'Madadhain
 * @author Omar Darwish
 * @param <N> Node parameter type
 * @param <E> Edge parameter type
 */
@ElementTypesAreNonnullByDefault
final class StandardMutableNetwork<N, E> extends StandardNetwork<N, E>
    implements MutableNetwork<N, E> {

  /** Constructs a mutable graph with the properties specified in {@code builder}. */
  StandardMutableNetwork(NetworkBuilder<? super N, ? super E> builder) {