/**
 Produces a random string between `'A'` and the inclusive `upper` bound

 @param upper - Inclusive upper bound
 @returns Random string
 */
export default function random(upper: string): string;
/**
 Produces a random string between the inclusive `lower` and `upper` bounds

 @param lower - Inclusive lower bound
 @param upper - Inclusive upper bound
 @returns Random string
 */
export default function random(lower: string, upper: string): string;