*   <li>graphs whose nodes/edges are insertion-ordered, sorted, or unordered
 *   <li>graphs whose edges have associated values
 * </ul>
 *
 * <p>{@code ValueGraph}, as a subtype of {@code Graph}, explicitly does not support parallel edges,
 * and forbids implementations or extensions with parallel edges. If you need parallel edges, use
 * {@link Network}. (You can use a positive {@code Integer} edge value as a loose representation of

  /**
   * Returns the nodes which are the endpoints of {@code edge} in this network.
   *
   * @throws IllegalArgumentException if {@code edge} is not an element of this network
   */
  EndpointPair<N> incidentNodes(E edge);

  /**
   * Returns a live view of the edges which have an {@link #incidentNodes(Object) incident node} in
   * common with {@code edge}. An edge is not considered adjacent to itself.
   *

    for (N node : graph.nodes()) {
      copy.addNode(node);
    }
    for (EndpointPair<N> edge : graph.edges()) {
      copy.putEdge(edge.nodeU(), edge.nodeV());
    }
    return copy;
  }

  /** Creates a mutable copy of {@code graph} with the same nodes, edges, and edge values. */
  public static <N, V> MutableValueGraph<N, V> copyOf(ValueGraph<N, V> graph) {
    MutableValueGraph<N, V> copy =

  @Override
  Set<N> nodes();

  /** Returns all edges in this graph. */
  @Override
  Set<EndpointPair<N>> edges();

  //
  // Graph properties
  //

  /**
   * Returns true if the edges in this graph are directed. Directed edges connect a {@link
   * EndpointPair#source() source node} to a {@link EndpointPair#target() target node}, while
   * undirected edges connect a pair of nodes to each other.
   */

        checkArgument(edges().contains(edge));
        N nodeU = edge.nodeU();
        N nodeV = edge.nodeV();
        Set<EndpointPair<N>> endpointPairIncidentEdges =
            Sets.union(incidentEdges(nodeU), incidentEdges(nodeV));
        return nodePairInvalidatableSet(
            Sets.difference(endpointPairIncidentEdges, ImmutableSet.of(edge)), nodeU, nodeV);
      }

  @Test
  public void edges_checkReturnedSetMutability() {
    assume().that(graphIsMutable()).isTrue();

    Set<String> edges = network.edges();
    assertThrows(UnsupportedOperationException.class, () -> edges.add(E12));
    addEdge(N1, N2, E12);
    assertThat(network.edges()).containsExactlyElementsIn(edges);
  }

  @Override
  @Test
  public void incidentEdges_checkReturnedSetMutability() {

    ImmutableSet<String> edges = ImmutableSet.copyOf(network.edges());
    assertThat(networkAsMutableNetwork.addEdge(N1, N2, E12)).isFalse();
    assertThat(network.edges()).containsExactlyElementsIn(edges);
    assertThat(networkAsMutableNetwork.addEdge(N2, N1, E12)).isFalse();
    assertThat(network.edges()).containsExactlyElementsIn(edges);
  }

  @Test

            throw new MetadataResolutionException("badly formed edge");
        }
    }
    // ------------------------------------------------------------------------
    public List<MetadataGraphEdge> getEdgesBetween(MetadataGraphVertex vFrom, MetadataGraphVertex vTo) {
        List<MetadataGraphEdge> edges = getIncidentEdges(vTo);
        if (edges == null || edges.isEmpty()) {
            return null;
        }

    ImmutableSet<String> edges = ImmutableSet.copyOf(network.edges());
    assertThat(networkAsMutableNetwork.addEdge(N1, N2, E12)).isFalse();
    assertThat(network.edges()).containsExactlyElementsIn(edges);
    assertThat(networkAsMutableNetwork.addEdge(N2, N1, E12)).isFalse();
    assertThat(network.edges()).containsExactlyElementsIn(edges);
  }

  @Test

    discussions = get_graphql_translation_discussions(settings=settings)
    lang_to_discussion_map: dict[str, AllDiscussionsDiscussionNode] = {}
    for discussion in discussions:
        for edge in discussion.labels.edges:
            label = edge.node.name
            if label.startswith("lang-") and not label == lang_all_label:
                lang = label[5:]
                lang_to_discussion_map[lang] = discussion