// TODO not sure that it should assume this, maybe the calls to addMetadata should pre-merge, then artifact
        // replaces?
        AbstractRepositoryMetadata repoMetadata = (AbstractRepositoryMetadata) metadata;
        this.metadata.merge(repoMetadata.getMetadata());
    }

    public void merge(ArtifactMetadata metadata) {

     */
    @Override
    public ModelTransformerContext initialize(ModelBuilderRequest request, ModelProblemCollector collector) {
        // We must assume the TransformerContext was created using this.newTransformerContextBuilder()
        DefaultModelProblemCollector problems = (DefaultModelProblemCollector) collector;
        return new ModelTransformerContext() {

  /** Test an empty collection. */
  ZERO(0),
  /** Test a one-element collection. */
  ONE(1),
  /** Test a three-element collection. */
  SEVERAL(3),
  /*
   * TODO: add VERY_LARGE, noting that we currently assume that the fourth
   * sample element is not in any collection
   */

  ANY(ZERO, ONE, SEVERAL);

  private final Set<Feature<? super Collection>> implied;
  private final @Nullable Integer numElements;

  public static <K extends Comparable, V extends @Nullable Object>
      Iterable<Entry<K, V>> orderEntriesByKey(List<Entry<K, V>> insertionOrder) {
    @SuppressWarnings("unchecked") // assume any Comparable is Comparable<Self>
    Comparator<? super K> keyComparator = (Comparator<? super K>) Comparable::compareTo;
    sort(insertionOrder, Helpers.entryComparator(keyComparator));
    return insertionOrder;
  }

              @Override
              public SortedMultiset<E> create(Object... entries) {
                @SuppressWarnings("unchecked")
                // we dangerously assume E is a string
                List<E> extremeValues = (List<E>) getExtremeValues();
                @SuppressWarnings("unchecked")
                // map generators must past entry objects

              @Override
              public SortedMultiset<E> create(Object... entries) {
                @SuppressWarnings("unchecked")
                // we dangerously assume E is a string
                List<E> extremeValues = (List<E>) getExtremeValues();
                @SuppressWarnings("unchecked")
                // map generators must past entry objects

  /** Test an empty collection. */
  ZERO(0),
  /** Test a one-element collection. */
  ONE(1),
  /** Test a three-element collection. */
  SEVERAL(3),
  /*
   * TODO: add VERY_LARGE, noting that we currently assume that the fourth
   * sample element is not in any collection
   */

  ANY(ZERO, ONE, SEVERAL);

  private final Set<Feature<? super Collection>> implied;
  private final @Nullable Integer numElements;

                .getSampleElements(getSubjectGenerator().getCollectionSize().getNumElements()));
    Collections.sort(entries, Helpers.<K, V>entryComparator(navigableMap.comparator()));

    // some tests assume SEVERAL == 3
    if (entries.size() >= 1) {
      a = entries.get(0);
      if (entries.size() >= 3) {
        b = entries.get(1);
        c = entries.get(2);
      }
    }
  }

                .getSampleElements(getSubjectGenerator().getCollectionSize().getNumElements()));
    Collections.sort(entries, Helpers.<K, V>entryComparator(navigableMap.comparator()));

    // some tests assume SEVERAL == 3
    if (entries.size() >= 1) {
      a = entries.get(0);
      if (entries.size() >= 3) {
        b = entries.get(1);
        c = entries.get(2);
      }
    }
  }

   * contents to empty. By contrast, the non-GWT constructor with the same signature uses the
   * comparator only as a comparator. It does NOT assume empty contents. (It requires an
   * implementation of iterator() to define its contents, and methods like contains() are
   * implemented in terms of that method (though they will likely be overridden by subclasses for