import { PipelineOperator } from "../../core";
/**
 * Processes multiple aggregation pipelines within a single stage on the same set of input documents.
 *
 * See {@link https://www.mongodb.com/docs/manual/reference/operator/aggregation/facet usage}.
 *
 * @param collection
 * @param expr
 * @param options
 * @returns
 */
export declare const $facet: PipelineOperator;