*
   * @throws IndexOutOfBoundsException if {@code index} is negative, or greater than or equal to
   *     {@link #length}
   */
  public double get(int index) {
    Preconditions.checkElementIndex(index, length());
    return array[start + index];
  }

  /**
   * Returns the smallest index for which {@link #get} returns {@code target}, or {@code -1} if no