/**
 * Copyright 2020 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
import { Descriptor } from '../descriptor';
import { CallSettings } from '../gax';
import { NormalApiCaller } from '../normalCalls/normalApiCaller';
import { BundleApiCaller } from './bundleApiCaller';
/**
 * A descriptor for calls that can be bundled into one call.
 */
export declare class BundleDescriptor implements Descriptor {
    bundledField: string;
    requestDiscriminatorFields: string[];
    subresponseField: string | null;
    byteLengthFunction: Function;
    /**
     * Describes the structure of bundled call.
     *
     * requestDiscriminatorFields may include '.' as a separator, which is used to
     * indicate object traversal. This allows fields in nested objects to be used
     * to determine what request to bundle.
     *
     * @property {String} bundledField
     * @property {String} requestDiscriminatorFields
     * @property {String} subresponseField
     * @property {Function} byteLengthFunction
     *
     * @param {String} bundledField - the repeated field in the request message
     *   that will have its elements aggregated by bundling.
     * @param {String} requestDiscriminatorFields - a list of fields in the
     *   target request message class that are used to detemrine which request
     *   messages should be bundled together.
     * @param {String} subresponseField - an optional field, when present it
     *   indicates the field in the response message that should be used to
     *   demultiplex the response into multiple response messages.
     * @param {Function} byteLengthFunction - a function to obtain the byte
     *   length to be consumed for the bundled field messages. Because Node.JS
     *   protobuf.js/gRPC uses builtin Objects for the user-visible data and
     *   internally they are encoded/decoded in protobuf manner, this function
     *   is actually necessary to calculate the byte length.
     * @constructor
     */
    constructor(bundledField: string, requestDiscriminatorFields: string[], subresponseField: string | null, byteLengthFunction: Function);
    getApiCaller(settings: CallSettings): NormalApiCaller | BundleApiCaller;
}