*
     * @return the root node of the dependency graph or {@code null} if none
     */
    @Nullable
    Node getRoot();

    /**
     * The ordered list of the flattened dependency nodes.
     *
     * @return the ordered list of the flattened dependency nodes
     */
    @Nonnull
    List<Node> getNodes();

    /**

		e := d.Cache[id]
		if len(e.Children) > 0 {
			e = d.flatten(e)
		}
		m[id] = e
	}
	return m
}

// flatten all children of the root into the root element and return it.
func (d *dataUsageCache) flatten(root dataUsageEntry) dataUsageEntry {
	for id := range root.Children {
		e := d.Cache[id]
		if len(e.Children) > 0 {
			e = d.flatten(e)
		}
		root.merge(e)
	}
	root.Children = nil

	CompName1 string `gorm:"index:,unique,composite:idx_compname_1,option:NULLS NOT DISTINCT;not null"`
	CompName2 string `gorm:"index:,composite:idx_compname_1"`

	// Composite Index: Flattened structure.
	Data0A string `gorm:"index:,composite:comp_id0"`
	Data0B string `gorm:"index:,composite:comp_id0"`

	// Composite Index: Nested structure.
	Data1A string `gorm:"index:,composite:comp_id1"`
	CompIdxLevel1C

            identifiers.put(ident, method);
          }
        }
      }
    }
    return ImmutableList.copyOf(identifiers.values());
  }

  /** Global cache of classes to their flattened hierarchy of supertypes. */
  private static final LoadingCache<Class<?>, ImmutableSet<Class<?>>> flattenHierarchyCache =
      CacheBuilder.newBuilder()
          .weakKeys()
          .build(

    /**
     * Shortcut for {@code getService(DependencyResolver.class).flatten(...)}.
     *
     * @param node node for which to get a flattened list
     * @param scope build path scope (main compile, test compile, etc.) of desired nodes
     * @return flattened list of node with the given build path scope

 * map from keys to <i>nonempty</i> collections of values:
 *
 * <ul>
 *   <li>a → 1, 2
 *   <li>b → 3
 * </ul>
 *
 * ... or as a single "flattened" collection of key-value pairs:
 *
 * <ul>
 *   <li>a → 1
 *   <li>a → 2
 *   <li>b → 3
 * </ul>
 *
 * <p><b>Important:</b> although the first interpretation resembles how most multimaps are

		path       string
		isNil      bool
		size, objs int
		flatten    bool
		oSizes     sizeHistogram
	}{
		{
			path:    "/",
			size:    363515,
			flatten: true,
			objs:    14,
			oSizes:  sizeHistogram{0: 7, 1: 5, 2: 2},
		},
		{
			path:    "/dir1",
			size:    342210,
			objs:    7,
			flatten: false,
			oSizes:  sizeHistogram{0: 2, 1: 3, 2: 2},
		},
		{

    /**
     * Should upgrade plugins known to fail with Maven 4 to their minimum compatible versions.
     * This includes upgrading plugins like maven-exec-plugin, maven-enforcer-plugin,
     * flatten-maven-plugin, and maven-shade-plugin to versions that work with Maven 4.
     *
     * @return an {@link Optional} containing the boolean value {@code true} if specified, or empty
     */
    @Nonnull

 * followed by <dfn>flattening</dfn> and <dfn>resolution</dfn>.
 * The version selection is done for each dependency during the collection phase.
 * The flatten phase keeps only a single version per ({@code groupId}, {@code artifactId}) pair.
 * The resolution phase actually downloads the dependencies (or artifacts) that have been computed.
 *
 * @since 4.0.0
 */
@Experimental

					// updates-collector goroutine still
					// holds a reference to this.
					wg.Wait()
					continue
				}

				wg.Wait()
				// Flatten for upstream, but save full state.
				var root dataUsageEntry
				if r := cache.root(); r != nil {
					root = cache.flatten(*r)
				}
				select {
				case <-ctx.Done():
					return
				case bucketResults <- dataUsageEntryInfo{
					Name:   cache.Info.Name,