protected abstract Map<String, String> create(Entry<String, String>[] entries);

  @Override
  @SuppressWarnings("unchecked")
  public final Entry<String, String>[] createArray(int length) {
    return (Entry<String, String>[]) new Entry<?, ?>[length];
  }

  @Override
  public final String[] createKeyArray(int length) {
    return new String[length];
  }

  @Override
  public final String[] createValueArray(int length) {

          {new MapRetrievalCache<String, String>(new HashMap<String, String>())},
          {new MapRetrievalCache<String, String>(new TreeMap<String, String>(nullsLast))}
        });
  }

  @Before
  public void init() {
    mapCache.clear();
  }

  @Test
  public void testKeySetIterator() {
    mapCache.put("A", "A_value");

  }

  static TestSuite suiteForString(
      CharSourceFactory factory, String string, String name, String desc) {
    TestSuite suite = new TestSuite(name + " [" + desc + "]");
    for (Method method : testMethods) {
      suite.addTest(new CharSourceTester(factory, string, name, desc, method));
    }
    return suite;
  }

  private final ImmutableList<String> expectedLines;

  private CharSource source;

        @Override
        public Map<String, String[]> getFields() {
            final Map<String, String[]> fields = new HashMap<>();
            for (final Map.Entry<String, String[]> entry : request.getParameterMap().entrySet()) {
                final String key = entry.getKey();
                if (key.startsWith("fields.")) {
                    final String[] value = simplifyArray(entry.getValue());

  protected abstract BiMap<String, String> create(Entry<String, String>[] entries);

  @Override
  @SuppressWarnings("unchecked")
  public final Entry<String, String>[] createArray(int length) {
    return (Entry<String, String>[]) new Entry<?, ?>[length];
  }

  @Override
  public final String[] createKeyArray(int length) {
    return new String[length];
  }

  @Override
  public final String[] createValueArray(int length) {

  protected abstract BiMap<String, String> create(Entry<String, String>[] entries);

  @Override
  @SuppressWarnings("unchecked")
  public final Entry<String, String>[] createArray(int length) {
    return (Entry<String, String>[]) new Entry<?, ?>[length];
  }

  @Override
  public final String[] createKeyArray(int length) {
    return new String[length];
  }

  @Override
  public final String[] createValueArray(int length) {

        Map<String, Object> original = new HashMap<>();
        original.put("string", "test");
        original.put("number", 42);

        List<String> nestedList = new ArrayList<>();
        nestedList.add("nested1");
        nestedList.add("nested2");
        original.put("list", nestedList);

        Map<String, String> nestedMap = new HashMap<>();

        }

        boolean isOutdated(String timestamp) {
            return timestamp != null && timestamp.compareTo(this.timestamp) > 0;
        }
    }

    private static class Key {

        private final String groupId;

        private final String artifactId;

        private final String classifier;

        private final String extension;

        private final String version;

    }

    protected MoreLikeThisQueryBuilder regMoreLikeThisQueryQ(String name, String[] likeTexts) {
        MoreLikeThisQueryBuilder moreLikeThisQuery = QueryBuilders.moreLikeThisQuery(new String[] { name }, likeTexts, null);
        regQ(moreLikeThisQuery);
        return moreLikeThisQuery;
    }

    protected SpanTermQueryBuilder regSpanTermQ(String name, String value) {
        checkEsInvalidQuery(name, value);

    @Override
    protected List<String> create(String[] elements) {
      return ImmutableList.copyOf(elements);
    }
  }

  public static class BuilderAddListGenerator extends TestStringListGenerator {
    @Override
    protected List<String> create(String[] elements) {
      ImmutableList.Builder<String> builder = ImmutableList.builder();
      for (String element : elements) {
        builder.add(element);