import { AnyParamConstructor } from '@typegoose/typegoose/lib/types';
import { PipelineStage } from 'mongoose';
import { AnyObject } from 'tn-typescript';
import { ExoAggrSuper } from '../ExoAggrSuper';
export declare class AggrStageAddFields<T extends AnyParamConstructor<any>> {
    $aggr: ExoAggrSuper<T>;
    private $fields;
    constructor($aggr: ExoAggrSuper<T>, fields?: AnyObject);
    pushFields(fields: AnyObject): this;
    get pipes(): PipelineStage[];
    clone($aggr: ExoAggrSuper<T>): AggrStageAddFields<T>;
}