export declare abstract class NightingaleElement {
    static readonly is: string;
}
declare type Selector = string | ((data: any) => any);
declare type Data = {
    payload: any;
    headers: Headers;
};
export declare const load: (url: string, headers?: Headers) => Promise<Data>;
declare class DataLoader extends HTMLElement implements NightingaleElement {
    private _errors;
    private _data;
    private _selector;
    static get is(): string;
    fetch(): Promise<void>;
    get data(): any;
    get loaded(): boolean;
    get errors(): Error[];
    get selector(): Selector;
    set selector(value: Selector);
    constructor();
    connectedCallback(): void;
}
export default DataLoader;