* implementations. Forked from {@link SetContainsBenchmark}.
 *
 * @author Nicholaus Shupe
 */
@NullUnmarked
public class MapBenchmark {
  @Param({"Hash", "LinkedHM", "MapMaker1", "Immutable"})
  private Impl impl;

  public enum Impl {
    Hash {
      @Override
      Map<Element, Element> create(Collection<Element> keys) {
        Map<Element, Element> map = new HashMap<>();