/**
 * 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 { GaxCall, GRPCCall } from './apitypes';
import { Descriptor } from './descriptor';
import { CallSettings } from './gax';
/**
 * Converts an rpc call into an API call governed by the settings.
 *
 * In typical usage, `func` will be a promise to a callable used to make an rpc
 * request. This will mostly likely be a bound method from a request stub used
 * to make an rpc call. It is not a direct function but a Promise instance,
 * because of its asynchronism (typically, obtaining the auth information).
 *
 * The result is a function which manages the API call with the given settings
 * and the options on the invocation.
 *
 * @param {Promise<GRPCCall>|GRPCCall} func - is either a promise to be used to make
 *   a bare RPC call, or just a bare RPC call.
 * @param {CallSettings} settings - provides the settings for this call
 * @param {Descriptor} descriptor - optionally specify the descriptor for
 *   the method call.
 * @return {GaxCall} func - a bound method on a request stub used
 *   to make an rpc call.
 */
export declare function createApiCall(func: Promise<GRPCCall> | GRPCCall, settings: CallSettings, descriptor?: Descriptor, _fallback?: boolean | 'proto' | 'rest'): GaxCall;