export declare const AddToSet: (expression: any) => {
    $addToSet: any;
};
export declare const Avg: (expression: any) => {
    $avg: any;
};
export declare const Max: (expression: any) => {
    $max: any;
};
export declare const Min: (expression: any) => {
    $min: any;
};
export declare const Push: (expression: any) => {
    $push: any;
};
export declare const StdDevPop: (expression: any) => {
    $stdDevPop: any;
};
export declare const StdDevSamp: (expression: any) => {
    $stdDevSamp: any;
};
export declare const Sum: (expression: any) => {
    $sum: any;
};