/**
 * Pads `string` on the left and right sides if it's shorter than `length`.
 * Padding characters are truncated if they can't be evenly divided by `length`.
 *
 * @static
 * @memberOf _
 * @since 3.0.0
 * @category String
 * @param {string} [string=''] The string to pad.
 * @param {number} [length=0] The padding length.
 * @param {string} [chars=' '] The string used as padding.
 * @returns {string} Returns the padded string.
 * @example
 *
 * _.pad('abc', 8);
 * // => '  abc   '
 *
 * _.pad('abc', 8, '_-');
 * // => '_-abc_-_'
 *
 * _.pad('abc', 3);
 * // => 'abc'
 */
export default function pad(str: string, length: number, chars: string): string;