import { Iterator } from "../../lazy";
import { AnyObject, Options } from "../../types";
/**
 * 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}.
 */
export declare function $facet(coll: Iterator, expr: Record<string, AnyObject[]>, options: Options): Iterator;