}
      ArrayList<EndpointPair<Integer>> edgeList = new ArrayList<>(graph.edges());

      assertThat(graph.nodes()).hasSize(NUM_NODES);
      assertThat(graph.edges()).hasSize(NUM_EDGES);
      AbstractGraphTest.validateGraph(graph);

      Collections.shuffle(edgeList, gen);
      int numEdgesToRemove = gen.nextInt(NUM_EDGES);
      for (int i = 0; i < numEdgesToRemove; ++i) {
        EndpointPair<Integer> edge = edgeList.get(i);

            .isTrue();
      }
      ArrayList<Object> edgeList = new ArrayList<>(network.edges());

      assertThat(network.nodes()).hasSize(NUM_NODES);
      assertThat(network.edges()).hasSize(NUM_EDGES);
      AbstractNetworkTest.validateNetwork(network);

      Collections.shuffle(edgeList, gen);
      int numEdgesToRemove = gen.nextInt(NUM_EDGES);
      for (int i = 0; i < numEdgesToRemove; ++i) {
        Object edge = edgeList.get(i);

 */
@ElementTypesAreNonnullByDefault
abstract class AbstractDirectedNetworkConnections<N, E> implements NetworkConnections<N, E> {
  /** Keys are edges incoming to the origin node, values are the source node. */
  final Map<E, N> inEdgeMap;

  /** Keys are edges outgoing from the origin node, values are the target node. */
  final Map<E, N> outEdgeMap;

  private int selfLoopCount;

        assertNotNull(res.getExcidentEdges(v1), "no edges in the resulting graph after resolver");

        assertEquals(4, res.getVertices().size(), "wrong # of vertices in the resulting graph after resolver");
        assertEquals(
                2,
                res.getExcidentEdges(v1).size(),
                "wrong # of excident edges in the resulting graph entry after resolver");

        assertEquals(

      }
      ArrayList<EndpointPair<Integer>> edgeList = new ArrayList<>(graph.edges());

      assertThat(graph.nodes()).hasSize(NUM_NODES);
      assertThat(graph.edges()).hasSize(NUM_EDGES);
      AbstractGraphTest.validateGraph(graph);

      Collections.shuffle(edgeList, gen);
      int numEdgesToRemove = gen.nextInt(NUM_EDGES);
      for (int i = 0; i < numEdgesToRemove; ++i) {
        EndpointPair<Integer> edge = edgeList.get(i);

 * user-defined properties.
 *
 * <p>A {@code Network} built by this class has the following default properties:
 *
 * <ul>
 *   <li>does not allow parallel edges
 *   <li>does not allow self-loops
 *   <li>orders {@link Network#nodes()} and {@link Network#edges()} in the order in which the
 *       elements were added (insertion order)
 * </ul>
 *

    private MetadataGraphEdge cleanEdges(
            MetadataGraphVertex v, List<MetadataGraphEdge> edges, ArtifactScopeEnum scope) {
        if (edges == null || edges.isEmpty()) {
            return null;
        }

        if (edges.size() == 1) {
            MetadataGraphEdge e = edges.get(0);
            if (scope.encloses(e.getScope())) {
                return e;
            }

    }


    /**
     * @param key
     *            7 or 8 byte DES key
     * @return DES cipher in encryption mode
     */
    public static Cipher getDES ( byte[] key ) {
        if ( key.length == 7 ) {
            return getDES(des7to8(key));
        }

        try {
            Cipher c = Cipher.getInstance("DES/ECB/NoPadding");
            c.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(key, "DES"));

    assertThat(edges).hasSize(2);
    assertThat(edges).contains(EndpointPair.unordered(N1, N1));
    assertThat(edges).contains(EndpointPair.unordered(N1, N2));
    assertThat(edges).contains(EndpointPair.unordered(N2, N1)); // equal to unordered(N1, N2)

    // ordered endpoints not compatible with undirected graph
    assertThat(edges).doesNotContain(EndpointPair.ordered(N1, N2));

    assertThat(edges).hasSize(2);
    assertThat(edges).contains(EndpointPair.unordered(N1, N1));
    assertThat(edges).contains(EndpointPair.unordered(N1, N2));
    assertThat(edges).contains(EndpointPair.unordered(N2, N1)); // equal to unordered(N1, N2)

    // ordered endpoints not compatible with undirected graph
    assertThat(edges).doesNotContain(EndpointPair.ordered(N1, N2));