/// <reference types="mongoose/types/aggregate" />
/// <reference types="mongoose/types/callback" />
/// <reference types="mongoose/types/collection" />
/// <reference types="mongoose/types/connection" />
/// <reference types="mongoose/types/cursor" />
/// <reference types="mongoose/types/document" />
/// <reference types="mongoose/types/error" />
/// <reference types="mongoose/types/expressions" />
/// <reference types="mongoose/types/helpers" />
/// <reference types="mongoose/types/middlewares" />
/// <reference types="mongoose/types/indexes" />
/// <reference types="mongoose/types/models" />
/// <reference types="mongoose/types/mongooseoptions" />
/// <reference types="mongoose/types/pipelinestage" />
/// <reference types="mongoose/types/populate" />
/// <reference types="mongoose/types/query" />
/// <reference types="mongoose/types/schemaoptions" />
/// <reference types="mongoose/types/schematypes" />
/// <reference types="mongoose/types/session" />
/// <reference types="mongoose/types/types" />
/// <reference types="mongoose/types/utility" />
/// <reference types="mongoose/types/validation" />
/// <reference types="mongoose/types/virtuals" />
/// <reference types="mongoose/types/inferschematype" />
/// <reference types="mongoose/types/inferrawdoctype" />
import { Types } from 'mongoose';
/**
 * Normalizes a principalId to the correct type for MongoDB queries and storage.
 * USER and GROUP principals are stored as ObjectIds; ROLE principals are strings.
 * Ensures a string caller ID is cast to ObjectId so it matches documents written
 * by `grantCapability` — which always stores user/group IDs as ObjectIds to match
 * what `getUserPrincipals` returns.
 */
export declare const normalizePrincipalId: (principalId: string | Types.ObjectId, principalType: PrincipalType) => string | Types.ObjectId;