this.height = 1 + Math.max(height(left), height(right));
    }

    private void recompute() {
      recomputeMultiset();
      recomputeHeight();
    }

    private AvlNode<E> rebalance() {
      switch (balanceFactor()) {
        case -2:
          // requireNonNull is safe because right must exist in order to get a negative factor.
          requireNonNull(right);
          if (right.balanceFactor() > 0) {

            "one", 1,
            "two", 2,
            "three", 3,
            "four", 4,
            "five", 5,
            "six", 6,
            "seven", 7,
            "eight", 8),
        "eight",
        8,
        "five",
        5,
        "four",
        4,
        "one",
        1,
        "seven",
        7,
        "six",
        6,
        "three",

  /**
   * The HTTP <a
   * href="https://wicg.github.io/responsive-image-client-hints/#sec-ch-viewport-height">{@code
   * Sec-CH-Viewport-Height}</a> header field name.
   *
   * @since 32.0.0
   */
  public static final String SEC_CH_VIEWPORT_HEIGHT = "Sec-CH-Viewport-Height";
  /**
   * The HTTP <a href="https://wicg.github.io/responsive-image-client-hints/#sec-ch-dpr">{@code

 * named analogously to their {@code BigInteger} counterparts.
 *
 * <p>The implementations of many methods in this class are based on material from Henry S. Warren,
 * Jr.'s <i>Hacker's Delight</i>, (Addison Wesley, 2002).
 *
 * <p>Similar functionality for {@code int} and for {@link BigInteger} can be found in {@link
 * IntMath} and {@link BigIntegerMath} respectively. For other common operations on {@code long}

  public static final Integer four = 4;
  public static final Integer five = 5;
  public static final Integer six = 6;
  public static final Integer seven = 7;
  public static final Integer eight = 8;
  public static final Integer nine = 9;
  public static final Integer m1 = -1;
  public static final Integer m2 = -2;
  public static final Integer m3 = -3;
  public static final Integer m4 = -4;

      ValueReference<K, V> previous = entry.getValueReference();
      int weight = map.weigher.weigh(key, value);
      checkState(weight >= 0, "Weights must be non-negative");

      ValueReference<K, V> valueReference =
          map.valueStrength.referenceValue(this, entry, value, weight);
      entry.setValueReference(valueReference);
      recordWrite(entry, weight, now);
      previous.notifyNewValue(value);
    }

            "five", 5,
            "six", 6,
            "seven", 7,
            "eight", 8),
        "one",
        1,
        "two",
        2,
        "three",
        3,
        "four",
        4,
        "five",
        5,
        "six",
        6,
        "seven",
        7,
        "eight",
        8);
    assertMapEquals(
        ImmutableBiMap.of(
            "one", 1,

            "five", 5,
            "six", 6,
            "seven", 7,
            "eight", 8),
        "one",
        1,
        "two",
        2,
        "three",
        3,
        "four",
        4,
        "five",
        5,
        "six",
        6,
        "seven",
        7,
        "eight",
        8);
    assertMapEquals(
        ImmutableMap.of(
            "one", 1,

  public static final Integer four = 4;
  public static final Integer five = 5;
  public static final Integer six = 6;
  public static final Integer seven = 7;
  public static final Integer eight = 8;
  public static final Integer nine = 9;
  public static final Integer m1 = -1;
  public static final Integer m2 = -2;
  public static final Integer m3 = -3;
  public static final Integer m4 = -4;

   * java.nio.charset.StandardCharsets#ISO_8859_1} instead.
   *
   */
  public static final Charset ISO_8859_1 = Charset.forName("ISO-8859-1");

  /**
   * UTF-8: eight-bit UCS Transformation Format.
   *
   * <p><b>Java 7+ users:</b> this constant should be treated as deprecated; use {@link
   * java.nio.charset.StandardCharsets#UTF_8} instead.
   *
   */