/**
 * Return the microsecond (0-999) for a given ISO 8601 time string.
 *
 * @param value ISO time string
 * @returns Microsecond (000-999) or "" on invalid input
 *
 * @example parseMicrosecondFromTime("12:30:45.123") // "123"
 * @example parseMicrosecondFromTime("12:30:45.000") // "000"
 * @example parseMicrosecondFromTime("invalid") // ""
 */
export declare function parseMicrosecondFromTime(value: string): string;