import { GetJwtCallback } from '../Jwt';
import { IAccessToken, IAccessTokenProvider, ITokenContext } from './interfaces';
/**
 * Implementation of {@link IAccessToken} that calls the user-provided
 * callback function to get the JWT when requested by the clients.
 */
export declare class CallbackJwtProvider implements IAccessTokenProvider {
    private readonly getJwt;
    /**
     * Creates a new instance of `CallbackJwtProvider`.
     *
     * @param {GetJwtCallback} getJwtFn - The function that will be called
     * whenever the JWT is needed. If the `getJwtFn` returns the JWT as a
     * string, it will be converted to {@link Jwt} instance automatically.
     */
    constructor(getJwtFn: GetJwtCallback);
    /**
     * Returns a `Promise` resolved with the {@link Jwt} instance obtained
     * by the call to the {@link CallbackJwtProvider.getJwt}. If the
     * `getJwtFn` returns the JWT as a string, it is converted to
     * {@link Jwt} instance before returning.
     *
     * @param {ITokenContext} context
     * @returns {Promise<IAccessToken>}
     */
    getToken(context: ITokenContext): Promise<IAccessToken>;
}