import type { ErrorClass } from './types';
/**
 * Classify a code as `public` or `internal`.
 *
 * Unknown codes are classified `internal` on purpose: transports mask internal
 * errors, so an unregistered code is never leaked to end users by default.
 */
export declare function classify(code: string | null | undefined): ErrorClass;
/** Whether a code is registered and classified `public`. */
export declare function isPublicCode(code: string | null | undefined): boolean;