/**
 * {Api} class provides a single interface to make REST calls to the Elavon API.
 *
 */
export declare class Api {
    /**
     * Performs a REST call to the Elavon API.
     * @param {string} url - The relative url of the API endpoint.
     * @param {string} method - The HTTP request method.
     * @param {any} [params] - The request body or query string parameters.
     * @param {any} [cookies] - Cookies to be sent with the request.
     * @param {any} [headers] - Headers to be sent with the request.
     * @returns {Promise<any>} The response from the API.
     */
    static call(url: string, method: string, params?: any, cookies?: any, headers?: any): Promise<any>;
}