/**
 * @module formatter
 */
/**
 * @param source source string.
 * @param minLength
 * @param appender item appended on left side.
 *
 * ```ts
 * appendLeft('abc', 1) === 'abc'
 * appendLeft('abc', 5) === '00abc'
 * appendLeft('abc', 5, 'QA') === 'QAQAabc'
 * ```
 */
export declare function appendLeft(source: string | number, minLength: number, appender?: string | number): string;