*         .addNode(ICELAND)
   *         .build();
   * }</pre>
   *
   * <p>Builder instances can be reused; it is safe to call {@link #build} multiple times to build
   * multiple graphs in series. Each new graph contains all the elements of the ones created before
   * it.
   *
   * @since 28.0
   */
  public static class Builder<N> {

    private final MutableGraph<N> mutableGraph;

   *         .addNode(REYKJAVIK)
   *         .build();
   * }</pre>
   *
   * <p>Builder instances can be reused; it is safe to call {@link #build} multiple times to build
   * multiple networks in series. Each new network contains all the elements of the ones created
   * before it.
   *
   * @since 28.0
   */
  public static class Builder<N, E> {

    private final MutableNetwork<N, E> mutableNetwork;

import java.util.Set;

/**
 * Filter to only retain objects in the given scope or better. This implementation allows the accumulation of multiple
 * scopes and their associated implied scopes, so that the user can filter apply a series of implication rules in a
 * single step. This should be a more efficient implementation of multiple standard {@link ScopeArtifactFilter}
 * instances ORed together.
 *
 */

   *         .addNode(REYKJAVIK)
   *         .build();
   * }</pre>
   *
   * <p>Builder instances can be reused; it is safe to call {@link #build} multiple times to build
   * multiple graphs in series. Each new graph contains all the elements of the ones created before
   * it.
   *
   * @since 28.0
   */
  public static class Builder<N, V> {

    private final MutableValueGraph<N, V> mutableValueGraph;