* changes to the graph (if the graph is mutable) but may not be modified by the user.
 *
 * <p>The time complexity of all collection-returning accessors is O(1), since views are returned.
 *
 * @author James Sexton
 * @author Joshua O'Madadhain
 * @author Omar Darwish
 * @param <N> Node parameter type
 * @param <E> Edge parameter type
 */
@ElementTypesAreNonnullByDefault

 *         .<String>immutable()
 *         .putEdge("bread", "bread")
 *         .putEdge("chocolate", "peanut butter")
 *         .putEdge("peanut butter", "jelly")
 *         .build();
 * }</pre>
 *
 * @author James Sexton
 * @author Joshua O'Madadhain
 * @param <N> The most general node type this builder will support. This is normally {@code Object}
 *     unless it is constrained by using a method like {@link #nodeOrder}, or the builder is

  }

  /** Constructs a listenable future with a value available after the latch has counted down. */
  protected abstract <V> ListenableFuture<V> createListenableFuture(
      V value, @Nullable Exception except, CountDownLatch waitOn);

  /** Tests that the {@link Future#get()} method blocks until a value is available. */
  public void testGetBlocksUntilValueAvailable() throws Throwable {

    assertFalse(future.isDone());

 * changes to the graph (if the graph is mutable) but may not be modified by the user.
 *
 * <p>The time complexity of all collection-returning accessors is O(1), since views are returned.
 *
 * @author James Sexton
 * @author Joshua O'Madadhain
 * @author Omar Darwish
 * @param <N> Node parameter type
 * @param <V> Value parameter type
 */
@ElementTypesAreNonnullByDefault

 * of the {@code Immutable*} types</a> for more information on the properties and guarantees
 * provided by this class.
 *
 * @author James Sexton
 * @author Joshua O'Madadhain
 * @author Omar Darwish
 * @author Jens Nyman
 * @param <N> Node parameter type
 * @param <E> Edge parameter type
 * @since 20.0
 */
@Beta
@Immutable(containerOf = {"N", "E"})

 * this class rather than implement {@link Network} directly.
 *
 * <p>The methods implemented in this class should not be overridden unless the subclass admits a
 * more efficient implementation.
 *
 * @author James Sexton
 * @param <N> Node parameter type
 * @param <E> Edge parameter type
 * @since 20.0
 */
@Beta
@ElementTypesAreNonnullByDefault
public abstract class AbstractNetwork<N, E> implements Network<N, E> {
  @Override

 * This class provides a skeletal implementation of {@link BaseGraph}.
 *
 * <p>The methods implemented in this class should not be overridden unless the subclass admits a
 * more efficient implementation.
 *
 * @author James Sexton
 * @param <N> Node parameter type
 */
@ElementTypesAreNonnullByDefault
abstract class AbstractBaseGraph<N> implements BaseGraph<N> {

  /**

import java.util.Set;
import java.util.concurrent.atomic.AtomicBoolean;
import javax.annotation.CheckForNull;

/**
 * An implementation of {@link GraphConnections} for directed graphs.
 *
 * @author James Sexton
 * @author Jens Nyman
 * @param <N> Node parameter type
 * @param <V> Value parameter type
 */
@ElementTypesAreNonnullByDefault
final class DirectedGraphConnections<N, V> implements GraphConnections<N, V> {
  /**

 * {@link EndpointPair} of an undirected edge is an unordered pair of nodes ({@link #nodeU()} and
 * {@link #nodeV()}).
 *
 * <p>The edge is a self-loop if, and only if, the two endpoints are equal.
 *
 * @author James Sexton
 * @since 20.0
 */
@Beta
@Immutable(containerOf = {"N"})
@ElementTypesAreNonnullByDefault
public abstract class EndpointPair<N> implements Iterable<N> {
  private final N nodeU;
  private final N nodeV;

 * of the {@code Immutable*} types</a> for more information on the properties and guarantees
 * provided by this class.
 *
 * @author James Sexton
 * @author Jens Nyman
 * @param <N> Node parameter type
 * @param <V> Value parameter type
 * @since 20.0
 */
@Beta
@Immutable(containerOf = {"N", "V"})