import { IConfig } from '../models/IConfig';
export declare class HeaderManager {
    private static readonly DEFAULT_USER_AGENT;
    private static readonly USER_AGENT_MAX_LENGTH;
    private static _userAgent;
    private _config;
    /**
     * Constructor
     * Create an instance of TibberBase class
     * @param {IConfig} config Config object
     * @see IConfig
     */
    constructor(config: IConfig);
    /**
     * Gets the User-Agent from apiEndpoint and ensures it is not changed once set.
     */
    get userAgent(): string;
    /**
     * Sanitize User-Agent string.
     *  - Remove all characters that are not allowed in User-Agent.
     *  - Limit the length to 255 characters.
     * @param {string} userAgent User-Agent string to sanitize.
     * @returns {string} Sanitized User-Agent string.
     * @see {@link https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/User-Agent}
     * @see {@link https://tools.ietf.org/html/rfc7231#section-5.5.3}
     * @see {@link https://tools.ietf.org/html/rfc7230#section-3.2.6}
     * @see {@link https://tools.ietf.org/html/rfc7230#section-5.5}
     *  */
    private sanitizeUserAgent;
}