* {@code expectedKeys} is a good estimate.
   *
   * @throws IllegalArgumentException if {@code expectedKeys} is negative
   * @since 33.3.0
   */
  public static <K, V> Builder<K, V> builderWithExpectedKeys(int expectedKeys) {
    checkNonnegative(expectedKeys, "expectedKeys");
    return new Builder<>(expectedKeys);
  }

  /**

     */
    public Builder(Comparator<? super E> comparator) {
      this.comparator = checkNotNull(comparator);
    }

    Builder(Comparator<? super E> comparator, int expectedKeys) {
      super(expectedKeys, false);
      this.comparator = checkNotNull(comparator);
    }

    /**
     * Adds {@code element} to the {@code ImmutableSortedSet}. If the {@code ImmutableSortedSet}