interface String {
    /**
     * Pads the current string with a given string (possibly repeated) so that the resulting string reaches a given length.
     * The padding is applied from the start (left) of the current string.
     *
     * @param maxLength The length of the resulting string once the current string has been padded.
     *        If this parameter is smaller than the current string's length, the current string will be returned as it is.
     *
     * @param fillString The string to pad the current string with.
     *        If this string is too long, it will be truncated and the left-most part will be applied.
     *        The default value for this parameter is " " (U+0020).
     */
    padStart(maxLength: number, fillString?: string): string;

    /**
     * Pads the current string with a given string (possibly repeated) so that the resulting string reaches a given length.
     * The padding is applied from the end (right) of the current string.
     *
     * @param maxLength The length of the resulting string once the current string has been padded.
     *        If this parameter is smaller than the current string's length, the current string will be returned as it is.
     *
     * @param fillString The string to pad the current string with.
     *        If this string is too long, it will be truncated and the left-most part will be applied.
     *        The default value for this parameter is " " (U+0020).
     */
    padEnd(maxLength: number, fillString?: string): string;
}