import { PipelineOperator } from "../../core";
/**
 * Categorizes incoming documents into groups, called buckets, based on a specified
 * expression and bucket boundaries and outputs a document per each bucket.
 *
 * See {@link https://docs.mongodb.com/manual/reference/operator/aggregation/bucket/ usage}.
 *
 * @param collection
 * @param expr
 * @param options
 * @returns
 */
export declare const $bucket: PipelineOperator;