/**
 * Wraps a function with caching capabilities.
 *
 * @param namespace - A unique namespace for the cache key.
 * @param handler - The function to be wrapped.
 * @param prepareArg - Optional function to prepare arguments for hashing.
 * @returns A new function that caches the results of the original function.
 *
 * @NOTE Ensure that the `namespace` is unique to avoid cache key collisions.
 * @NOTE Ensure that the `prepareArg` function returns a JSON stringifiable representation of the arguments.
 */
export declare function withCache<F extends (...args: any) => any>(namespace: string, handler: F, prepareArg?: (...args: Parameters<F>) => Record<string, unknown>): (...args: Parameters<F>) => Promise<Awaited<ReturnType<F>>>;