@Nullable Object[] alternatingKeysAndValues;
    int size;
    boolean entriesUsed;

    /**
     * If non-null, a duplicate key we found in a previous buildKeepingLast() or buildOrThrow()
     * call. A later buildOrThrow() can simply report this duplicate immediately.
     */
    @Nullable DuplicateKey duplicateKey;

    /**

   * collection in unspecified order.
   *
   * @param collection the elements that the set should contain
   * @return a new {@code CompactHashSet} containing those elements (minus duplicates)
   */
  public static <E extends @Nullable Object> CompactHashSet<E> create(
      Collection<? extends E> collection) {
    CompactHashSet<E> set = createWithExpectedSize(collection.size());
    set.addAll(collection);

 * elements.
 *
 * <p>The collections created by {@link #createCollection()} may or may not allow duplicates. If the
 * collection, such as a {@link Set}, does not support duplicates, an added key-value pair will
 * replace an existing pair with the same key and value, if such a pair is present. With collections
 * like {@link List} that allow duplicates, the collection will keep the existing key-value pairs
 * while adding a new pair.
 *

   *
   * <p>Because a {@code SetMultimap} has unique values for a given key, this method returns a
   * {@link Set}, instead of the {@link Collection} specified in the {@link Multimap} interface.
   *
   * <p>Any duplicates in {@code values} will be stored in the multimap once.
   */
  @CanIgnoreReturnValue
  @Override
  public Set<V> replaceValues(@ParametricNullness K key, Iterable<? extends V> values) {

    Map<Integer, String> expected = new LinkedHashMap<>();
    for (int i = 0; i < 1000; i++) {
      // Truncate to even key, so we have put(0, "0") then put(0, "1"). Half the entries are
      // duplicates.
      Integer key = i & ~1;
      String value = String.valueOf(i);
      builder.put(key, value);
      expected.put(key, value);
    }
    ImmutableMap<Integer, String> map = builder.buildKeepingLast();

			success: false,
		},
		// no duplicates, shall be parsed properly.
		{

 * During this process only the most relevant version of each artifact
 * (based on group ID and artifact ID) is retained, resolving conflicts and eliminating duplicates to ensure
 * that each dependency is included only once in the final build.</p>
 *
 * <p><dfn>Dependency resolution</dfn> is the process of collecting dependencies, flattening the result graph,

    }
  }

  // TODO: test adding element of wrong type

  /**
   * Returns {@link Method} instances for the {@code setCount()} tests that assume multisets support
   * duplicates so that the test of {@code Multisets.forSet()} can suppress them.
   */
  @J2ktIncompatible
  @GwtIncompatible // reflection
  public static List<Method> getSetCountDuplicateInitializingMethods() {
    return asList(

    @Override
    public void setUp() throws Exception {
        super.setUp();
        indexUpdateCallback = new FileListIndexUpdateCallbackImpl(null, null, 1);
    }

    /** Case 1: Normal merge (no duplicates) */
    public void test_mergeResponseData_noOverwrite() {
        Map<String, Object> dataMap = new HashMap<>();
        dataMap.put("a", "A0");
        Map<String, Object> responseDataMap = new HashMap<>();

    assertFalse(getMultiset().retainAll(singleton(e0())));
    expectContents(contents);
  }

  /**
   * Returns {@link Method} instances for the remove tests that assume multisets support duplicates
   * so that the test of {@code Multisets.forSet()} can suppress them.
   */
  @J2ktIncompatible
  @GwtIncompatible // reflection
  public static List<Method> getRemoveDuplicateInitializingMethods() {