/**
 * @private
 * @description Adds left padding to a string with the desired substring the provided number of times
 * @example stringPad(foo, 3, 'a'') // -> aaafoo
 * @param {string} value
 * @param {number} _targetLength
 * @param {string} _padString
 */
export declare function stringPad(value: string, _targetLength: number, _padString: string): string;