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

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

/**
 * A class to allow {@link Network} implementations to be backed by a provided delegate. This is not
 * currently planned to be released as a general-purpose forwarding class.
 *
 * @author James Sexton
 * @author Joshua O'Madadhain
 */
@ElementTypesAreNonnullByDefault
abstract class ForwardingNetwork<N, E> extends AbstractNetwork<N, E> {

  abstract Network<N, E> delegate();

  @Override

      <email />
      <organization />
      <roles>
        <role>Developer</role>
      </roles>
    </developer>
    <developer>
      <id>jtaylor</id>
      <name>James Taylor</name>
      <email>james@jamestaylor.org</email>
      <organization />
      <roles>
        <role>Developer</role>
      </roles>
    </developer>
    <developer>
      <id>dandiep</id>

      <email />
      <organization />
      <roles>
        <role>Developer</role>
      </roles>
    </developer>
    <developer>
      <id>jtaylor</id>
      <name>James Taylor</name>
      <email>james@jamestaylor.org</email>
      <organization />
      <roles>
        <role>Developer</role>
      </roles>
    </developer>
    <developer>
      <id>dandiep</id>

 * this class rather than implement {@link ValueGraph} 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 <V> Value parameter type
 * @since 20.0
 */
@Beta
@ElementTypesAreNonnullByDefault
public abstract class AbstractValueGraph<N, V> extends AbstractBaseGraph<N>

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

/**
 * A base implementation of {@link NetworkConnections} for undirected networks.
 *
 * @author James Sexton
 * @param <N> Node parameter type
 * @param <E> Edge parameter type
 */
@ElementTypesAreNonnullByDefault
abstract class AbstractUndirectedNetworkConnections<N, E> implements NetworkConnections<N, E> {

      <email></email>
      <organization></organization>
      <roles>
        <role>Developer</role>
      </roles>
    </developer>
    <developer>
      <id>jtaylor</id>
      <name>James Taylor</name>
      <email>james@jamestaylor.org</email>
      <organization></organization>
      <roles>
        <role>Developer</role>
      </roles>
    </developer>
    <developer>
      <id>dandiep</id>

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

/**
 * An implementation of {@link NetworkConnections} for directed networks with parallel edges.
 *
 * @author James Sexton
 * @param <N> Node parameter type
 * @param <E> Edge parameter type
 */
@ElementTypesAreNonnullByDefault
final class DirectedMultiNetworkConnections<N, E> extends AbstractDirectedNetworkConnections<N, E> {

 *         .<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

      <email />
      <organization />
      <roles>
        <role>Developer</role>
      </roles>
    </developer>
    <developer>
      <id>jtaylor</id>
      <name>James Taylor</name>
      <email>james@jamestaylor.org</email>
      <organization />
      <roles>
        <role>Developer</role>
      </roles>
    </developer>
    <developer>
      <id>dandiep</id>