cache.put(10, 100);
    cache.put(2, 52);

    asMap.replace(2, 79);
    asMap.replace(3, 60);

    assertEquals(null, cache.getIfPresent(3));
    assertEquals(null, asMap.get(3));

    assertEquals(Integer.valueOf(79), cache.getIfPresent(2));
    assertEquals(Integer.valueOf(79), asMap.get(2));

    asMap.replace(10, 100, 50);
    asMap.replace(2, 52, 99);

    map.put(one, three);
    assertNotified(listener, one, two, RemovalCause.REPLACED);

    Map<Object, Object> newMap = ImmutableMap.of(one, four);
    map.putAll(newMap);
    assertNotified(listener, one, three, RemovalCause.REPLACED);

    map.replace(one, five);
    assertNotified(listener, one, four, RemovalCause.REPLACED);

    map.replace(one, five, six);
    assertNotified(listener, one, five, RemovalCause.REPLACED);

    map.put(one, three);
    assertNotified(listener, one, two, RemovalCause.REPLACED);

    Map<Object, Object> newMap = ImmutableMap.of(one, four);
    map.putAll(newMap);
    assertNotified(listener, one, three, RemovalCause.REPLACED);

    map.replace(one, five);
    assertNotified(listener, one, four, RemovalCause.REPLACED);

    map.replace(one, five, six);
    assertNotified(listener, one, five, RemovalCause.REPLACED);

  ReaderInputStream(Reader reader, Charset charset, int bufferSize) {
    this(
        reader,
        charset
            .newEncoder()
            .onMalformedInput(CodingErrorAction.REPLACE)
            .onUnmappableCharacter(CodingErrorAction.REPLACE),
        bufferSize);
  }

  /**
   * Creates a new input stream that will encode the characters from {@code reader} into bytes using
   * the given character set encoder.
   *

  ReaderInputStream(Reader reader, Charset charset, int bufferSize) {
    this(
        reader,
        charset
            .newEncoder()
            .onMalformedInput(CodingErrorAction.REPLACE)
            .onUnmappableCharacter(CodingErrorAction.REPLACE),
        bufferSize);
  }

  /**
   * Creates a new input stream that will encode the characters from {@code reader} into bytes using
   * the given character set encoder.
   *

    // If duplicates are allowed, this map will track the last value for each duplicated key.
    // A second pass will retain only the first entry for that key, but with this last value. The
    // value will then be replaced by null, signaling that later entries with the same key should
    // be deleted.
    Map<K, @Nullable V> duplicates = null;
    int dupCount = 0;
    for (int i = 0; i < n; i++) {

    }
    return false;
  }

  @Override
  public boolean replace(K key, V oldValue, V newValue) {
    if (oldValue.equals(get(key))) {
      alertListenerIfPresent(key, oldValue, RemovalCause.REPLACED);
      put(key, newValue);
      return true;
    }
    return false;
  }

  @Override
  public V replace(K key, V value) {
    V currentValue = get(key);
    if (currentValue != null) {

    }
  }

  // Returned from removeAt() to iterator.remove()
  static class MoveDesc<E> {
    final E toTrickle;
    final E replaced;

    MoveDesc(E toTrickle, E replaced) {
      this.toTrickle = toTrickle;
      this.replaced = replaced;
    }
  }

  /** Removes and returns the value at {@code index}. */
  private E removeAndGet(int index) {
    E value = elementData(index);

       * as a compromise, we enable the optimization only on platforms that we specifically know to
       * work.
       *
       * In the future, the use of Unsafe.getLong() should be replaced by ByteBuffer.getLong(),
       * which will have an efficient native implementation in JDK 9.
       *
       */
      String arch = System.getProperty("os.arch");

     */
    open fun url(url: URL) = url(url.toString().toHttpUrl())

    /**
     * Sets the header named [name] to [value]. If this request already has any headers
     * with that name, they are all replaced.
     */
    open fun header(
      name: String,
      value: String,
    ) = commonHeader(name, value)

    /**
     * Adds a header with [name] and [value]. Prefer this method for multiply-valued