// Number of edges remaining is unknown (node's incident edges have been removed).
      AbstractGraphTest.validateGraph(graph);

      for (int i = numNodesToRemove; i < NUM_NODES; ++i) {
        assertThat(graph.removeNode(nodeList.get(i))).isTrue();
      }

      assertThat(graph.nodes()).isEmpty();
      assertThat(graph.edges()).isEmpty(); // no edges can remain if there's no nodes

  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: "

  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}.
   *

        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).
//

// declaration "type T int", we construct edges T<-A and T<-B with
// weight 1; and because of instantiation "f[T, map[A]B]" we construct
// edges A<-T with weight 0, and B<-A and B<-B with weight 1.
//
// Finally, we look for any positive-weight cycles. Zero-weight cycles
// are allowed because static instantiation will reach a fixed point.

type monoGraph struct {
	vertices []monoVertex
	edges    []monoEdge

// declaration "type T int", we construct edges T<-A and T<-B with
// weight 1; and because of instantiation "f[T, map[A]B]" we construct
// edges A<-T with weight 0, and B<-A and B<-B with weight 1.
//
// Finally, we look for any positive-weight cycles. Zero-weight cycles
// are allowed because static instantiation will reach a fixed point.

type monoGraph struct {
	vertices []monoVertex
	edges    []monoEdge

 * @since 23.0
 */
@Beta
@DoNotMock("Implement with a lambda, or use GraphBuilder to build a Graph with the desired edges")
@ElementTypesAreNonnullByDefault
public interface SuccessorsFunction<N> {

  /**
   * Returns all nodes in this graph adjacent to {@code node} which can be reached by traversing
   * {@code node}'s outgoing edges in the direction (if any) of the edge.
   *