@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.
   */

  @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.
   */

  BackEdgeHelper& operator=(const BackEdgeHelper& other) = delete;

  // Temporarily removes all the back edges in graph.
  Status Remove(Graph* graph);

  // Gets the list of removed edges.
  const std::vector<BackEdge>& RemovedEdges() const;

  // Replaces the back edges removed by a prior call to Remove.
  Status Replace();

 private:
  Graph* graph_ = nullptr;  // not owned

      return false;
    }
    Graph<?> other = (Graph<?>) obj;

    return isDirected() == other.isDirected()
        && nodes().equals(other.nodes())
        && edges().equals(other.edges());
  }

  @Override
  public final int hashCode() {
    return edges().hashCode();
  }

  /** Returns a string representation of this graph. */
  @Override
  public String toString() {
    return "isDirected: "

 * terms</a>):
 *
 * <ul>
 *   <li>directed graphs
 *   <li>undirected graphs
 *   <li>graphs that do/don't allow parallel edges
 *   <li>graphs that do/don't allow self-loops
 *   <li>graphs whose nodes/edges are insertion-ordered, sorted, or unordered
 *   <li>graphs whose edges are unique objects
 * </ul>
 *
 * <h3>Building a {@code Network}</h3>
 *

  Set<N> predecessors();

  Set<N> successors();

  Set<E> incidentEdges();

  Set<E> inEdges();

  Set<E> outEdges();

  /**
   * Returns the set of edges connecting the origin node to {@code node}. For networks without
   * parallel edges, this set cannot be of size greater than one.
   */
  Set<E> edgesConnecting(N node);

  /**
   * Returns the node that is adjacent to the origin node along {@code edge}.
   *

			b.Values = append(b.Values, v)

			// Find all the scheduling edges out from this value.
			i := sort.Search(len(edges), func(i int) bool {
				return edges[i].x.ID >= v.ID
			})
			j := sort.Search(len(edges), func(i int) bool {
				return edges[i].x.ID > v.ID
			})
			// Decrement inEdges for each target of edges from v.
			for _, e := range edges[i:j] {
				inEdges[e.y.ID]--
				if inEdges[e.y.ID] == 0 {

        emptyCompileState.hash == TestHashCodes.hashCodeFrom(0x12345678)
        emptyCompileState.edges == stateOne.edges

        def otherCompileState = newState.getState(fileTwo)
        otherCompileState.hash == TestHashCodes.hashCodeFrom(0x23456789)
        otherCompileState.edges == stateTwo.edges
    }

    private SourceFileState compilationFileState(HashCode hash, Collection<String> includes) {

    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;
            }

// -> ReadVariableOp1 and AssignVariableOp0 -> AssignVariableOp1 edges will be
// respected by XlaLaunchOp though because all reads happen before all writes
// with that limited clustering..
//
//
// NB!  The result computed by this analysis assumes that we don't auto-cluster
// back-edges (i.e. the edges from NextIteration to Merge).
//