import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Supplier;
import java.io.Serializable;
import java.util.LinkedHashMap;
import java.util.Map;

/**
 * Implementation of {@link Table} using linked hash tables. This guarantees predictable iteration
 * order of the various views.
 *
 * <p>The views returned by {@link #column}, {@link #columnKeySet()}, and {@link #columnMap()} have

            // System.err.println("Cleaned("+requestedScope+") graph("+res.getVertices().size()+"):\n"+res.toString());
            // System.err.println("Linked("+requestedScope+")
            // subgraph("+linkedRes.getVertices().size()+"):\n"+linkedRes.toString());
            return findLinkedSubgraph(res);
        } catch (MetadataResolutionException e) {

     *
     * @param dirtyGraph - dependency graph
     * @param scope - which classpath to extract
     * @param resolve - whether to resolve artifacts.
     * @return Collection of metadata objects in the linked subgraph of the graph which
     *             contains the graph.getEntry() vertice
     */
    ClasspathContainer transform(MetadataGraph dirtyGraph, ArtifactScopeEnum scope, boolean resolve)

   */
  @CheckForNull private transient int[] successor;

  /** Pointer to the first node in the linked list, or {@code ENDPOINT} if there are no entries. */
  private transient int firstEntry;

  /** Pointer to the last node in the linked list, or {@code ENDPOINT} if there are no entries. */
  private transient int lastEntry;

  CompactLinkedHashSet() {
    super();
  }

  private ExecutionSequencer() {}

  /** Creates a new instance. */
  public static ExecutionSequencer create() {
    return new ExecutionSequencer();
  }

  /** This reference acts as a pointer tracking the head of a linked list of ListenableFutures. */
  private final AtomicReference<ListenableFuture<@Nullable Void>> ref =
      new AtomicReference<>(immediateVoidFuture());