@CheckForNull
  K getKey();

  /*
   * Used by entries that use access order. Access entries are maintained in a doubly-linked list.
   * New entries are added at the tail of the list at write time; stale entries are expired from
   * the head of the list.
   */

  /** Returns the time that this entry was last accessed, in ns. */
  @SuppressWarnings("GoodTime")
  long getAccessTime();

  @CheckForNull
  K getKey();

  /*
   * Used by entries that use access order. Access entries are maintained in a doubly-linked list.
   * New entries are added at the tail of the list at write time; stale entries are expired from
   * the head of the list.
   */

  /** Returns the time that this entry was last accessed, in ns. */
  @SuppressWarnings("GoodTime")
  long getAccessTime();

    checkState(state != State.FAILED);
    switch (state) {
      case DONE:
        return false;
      case READY:
        return true;
      default:
    }
    return tryToComputeNext();
  }

  private boolean tryToComputeNext() {
    state = State.FAILED; // temporary pessimism
    next = computeNext();
    if (state != State.DONE) {
      state = State.READY;
      return true;
    }

import static com.google.common.util.concurrent.Service.State.FAILED;
import static com.google.common.util.concurrent.Service.State.NEW;
import static com.google.common.util.concurrent.Service.State.RUNNING;
import static com.google.common.util.concurrent.Service.State.STARTING;
import static com.google.common.util.concurrent.Service.State.STOPPING;
import static com.google.common.util.concurrent.Service.State.TERMINATED;

import java.util.Locale;

        AggregateFutureState<?> state, @CheckForNull Set<Throwable> expect, Set<Throwable> update) {
      synchronized (state) {
        if (state.seenExceptions == expect) {
          state.seenExceptions = update;
        }
      }
    }

    @Override
    int decrementAndGetRemainingCount(AggregateFutureState<?> state) {
      synchronized (state) {
        return --state.remaining;
      }

   * graphBuilder.incidentEdgeOrder(ElementOrder.stable())}.
   *
   * <h3>In combination with {@code incidentEdgeOrder}</h3>
   *
   * <p>{@code incidentEdgeOrder(ElementOrder.stable())} guarantees the ordering of the returned
   * collections of the following methods:
   *
   * <ul>
   *   <li>For {@link Graph} and {@link ValueGraph}:
   *       <ul>
   *         <li>{@code edges()}: Stable order

  }

  @Test
  public void incidentEdgeOrder_stable() {
    ImmutableValueGraph<String, Integer> immutableValueGraph =
        ImmutableValueGraph.copyOf(ValueGraphBuilder.directed().<String, Integer>build());

    assertThat(immutableValueGraph.incidentEdgeOrder()).isEqualTo(ElementOrder.stable());
  }

  @Test
  public void incidentEdgeOrder_fromUnorderedGraph_stable() {

    private static List<String> visitAll(
            Collection<Vertex> children, Map<Vertex, DfsState> stateMap, List<String> list) {
        for (Vertex v : children) {
            DfsState state = stateMap.putIfAbsent(v, DfsState.VISITING);
            if (state == null) {
                visitAll(v.children, stateMap, list);
                stateMap.put(v, DfsState.VISITED);
                list.add(v.label);
            }
        }

   * immutable graphs, this value is ignored; they always have a {@link ElementOrder#stable()
   * stable} order.
   *
   * @throws IllegalArgumentException if {@code incidentEdgeOrder} is not either {@code
   *     ElementOrder.unordered()} or {@code ElementOrder.stable()}.
   * @since 29.0
   */
  public <N1 extends N> ValueGraphBuilder<N1, V> incidentEdgeOrder(

            Map<String, DfsState> stateMap,
            LinkedList<String> cycle) {
        if (children != null) {
            for (String v : children) {
                DfsState state = stateMap.putIfAbsent(v, DfsState.VISITING);
                if (state == null) {
                    cycle.addLast(v);
                    List<String> ret = visitCycle(graph, graph.get(v), stateMap, cycle);
                    if (ret != null) {