}

  public void testBuilder() {
    ImmutableTable.Builder<Character, Integer, String> builder = new ImmutableTable.Builder<>();
    assertEquals(ImmutableTable.of(), builder.buildOrThrow());
    assertEquals(ImmutableTable.of('a', 1, "foo"), builder.put('a', 1, "foo").buildOrThrow());
    Table<Character, Integer, String> expectedTable = HashBasedTable.create();
    expectedTable.put('a', 1, "foo");
    expectedTable.put('b', 1, "bar");

    @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;

    /**

     *
     * <p>Prefer the equivalent method {@link #buildOrThrow()} to make it explicit that the method
     * will throw an exception if there are duplicate key pairs. The {@code build()} method will
     * soon be deprecated.
     *
     * @throws IllegalArgumentException if duplicate key pairs were added
     */
    public ImmutableTable<R, C, V> build() {
      return buildOrThrow();
    }

    /**

   * Builder.buildKeepingLast(). The same Builder might be called with buildKeepingLast() and then
   * buildOrThrow(), or vice versa. So in particular, if we modify alternatingKeysAndValues to
   * eliminate duplicate keys (for buildKeepingLast()) then we have to ensure that a later call to
   * buildOrThrow() will still throw as if the duplicates had not been eliminated. And the exception

     *
     * <p>Prefer the equivalent method {@link #buildOrThrow()} to make it explicit that the method
     * will throw an exception if there are duplicate key pairs. The {@code build()} method will
     * soon be deprecated.
     *
     * @throws IllegalArgumentException if duplicate key pairs were added
     */
    public ImmutableTable<R, C, V> build() {
      return buildOrThrow();
    }

    /**

     *
     * <p>Prefer the equivalent method {@link #buildOrThrow()} to make it explicit that the method
     * will throw an exception if there are duplicate keys. The {@code build()} method will soon be
     * deprecated.
     *
     * @throws IllegalArgumentException if duplicate keys were added
     */
    public ImmutableMap<K, V> build() {
      return buildOrThrow();
    }

    /**

     * <p>Prefer the equivalent method {@link #buildOrThrow()} to make it explicit that the method
     * will throw an exception if there are duplicate keys or values. The {@code build()} method
     * will soon be deprecated.
     *
     * @throws IllegalArgumentException if duplicate keys or values were added
     */
    @Override
    public ImmutableBiMap<K, V> build() {
      return buildOrThrow();
    }

    /**

     * <p>Prefer the equivalent method {@link #buildOrThrow()} to make it explicit that the method
     * will throw an exception if there are duplicate keys or values. The {@code build()} method
     * will soon be deprecated.
     *
     * @throws IllegalArgumentException if duplicate keys or values were added
     */
    @Override
    public ImmutableBiMap<K, V> build() {
      return buildOrThrow();
    }

    /**

        ImmutableMap.Builder<K, V>::new,
        (builder, input) -> builder.put(keyFunction.apply(input), valueFunction.apply(input)),
        ImmutableMap.Builder::combine,
        ImmutableMap.Builder::buildOrThrow);
  }

  static <T extends @Nullable Object, K, V> Collector<T, ?, ImmutableMap<K, V>> toImmutableMap(
      Function<? super T, ? extends K> keyFunction,
      Function<? super T, ? extends V> valueFunction,

        ImmutableMap.Builder<K, V>::new,
        (builder, input) -> builder.put(keyFunction.apply(input), valueFunction.apply(input)),
        ImmutableMap.Builder::combine,
        ImmutableMap.Builder::buildOrThrow);
  }

  static <T extends @Nullable Object, K, V> Collector<T, ?, ImmutableMap<K, V>> toImmutableMap(
      Function<? super T, ? extends K> keyFunction,
      Function<? super T, ? extends V> valueFunction,