/// <reference types="node" />
import * as stream from 'stream';
import { JWTInput } from './credentials';
import { RequestMetadataResponse } from './oauth2client';
export declare class JWTAccess {
    email?: string | null;
    key?: string | null;
    projectId?: string;
    /**
     * JWTAccess service account credentials.
     *
     * Create a new access token by using the credential to create a new JWT token
     * that's recognized as the access token.
     *
     * @param {string=} email the service account email address.
     * @param {string=} key the private key that will be used to sign the token.
     * @constructor
     */
    constructor(email?: string | null, key?: string | null);
    /**
     * Indicates whether the credential requires scopes to be created by calling
     * createdScoped before use.
     *
     * @return {boolean} always false
     */
    createScopedRequired(): boolean;
    /**
     * Get a non-expired access token, after refreshing if necessary
     *
     * @param {string} authURI the URI being authorized
     * @param {function} metadataCb a callback invoked with the jwt request metadata.
     * @returns a Promise that resolves with the request metadata response
     */
    getRequestMetadata(authURI: string): RequestMetadataResponse;
    /**
     * Create a JWTAccess credentials instance using the given input options.
     * @param {object=} json The input object.
     */
    fromJSON(json: JWTInput): void;
    /**
     * Create a JWTAccess credentials instance using the given input stream.
     * @param {object=} inputStream The input stream.
     * @param {function=} callback Optional callback.
     */
    fromStream(inputStream: stream.Readable): Promise<void>;
    fromStream(inputStream: stream.Readable, callback: (err?: Error) => void): void;
    private fromStreamAsync(inputStream);
}