public interface CollectionsImplEnum {
    <E extends Comparable<E>> Collection<E> create(Collection<E> contents);

    String name();
  }

  public interface MapsImplEnum {
    <K extends Comparable<K>, V> Map<K, V> create(Map<K, V> contents);

    String name();
  }

  public interface InternerImplEnum {
    <E> Interner<E> create(Collection<E> contents);