export interface RequestError {
    status: number;
    response: string;
    url: string;
    headers?: any;
}
export interface RequestRejector {
    (err: RequestError): any;
}
export default class DataFetcher {
    basicAuthKey: string;
    private proxyUrl;
    private adapter;
    constructor(config?: {
        proxyUrl?: string;
        adapter?: any;
    });
    fetchOPDSData(url: string): Promise<{}>;
    fetchSearchDescriptionData(searchDescriptionUrl: string): Promise<{}>;
    fetch(url: string, options?: {}): Promise<IResponse>;
    setBasicAuthCredentials(credentials: string): void;
    getBasicAuthCredentials(): string;
    clearBasicAuthCredentials(): void;
    prepareBasicAuthHeaders(headers?: any): any;
    isErrorCode(status: number): boolean;
}