declare class Fetch {
    baseURL: string;
    defaultHeaders: Record<string, string>;
    constructor(config?: {
        baseURL?: string;
        headers?: Record<string, string>;
    });
    query(options: {
        url: string;
        method?: string;
        headers?: Record<string, any>;
        cache?: RequestCache;
    }, params?: object): Promise<string>;
    request(url: string, args?: {
        params?: Record<string, any>;
        method?: 'POST' | 'GET';
        baseURL?: string;
        headers?: Record<string, string>;
        cache?: RequestCache;
    }): Promise<string>;
    formatError(response: Response | null, responseText: string | null, networkError?: any): any;
    ask(url: string, args?: {
        params?: Record<string, any>;
        method?: 'POST' | 'GET';
        baseURL?: string;
        headers?: Record<string, string>;
        cache?: RequestCache;
    }): Promise<[null, any] | [any, undefined]>;
}
declare const _default: {
    getDataURL: (url: string, init?: RequestInit | undefined) => Promise<[any, undefined] | [null, {
        contentType: string;
        dataUrl: string;
    }]>;
    getArrayBuffer: (url: string, init?: RequestInit | undefined) => Promise<[any, undefined] | [null, ArrayBuffer]>;
    getJson: (url: string, init?: RequestInit | undefined) => Promise<[null, any] | [any, undefined]>;
    download: (url: string, opts?: {
        success?: ((buffer: Uint8Array) => void) | undefined;
        progress?: ((percentage: number, current: number, total: number) => void) | undefined;
        fail?: ((error: Error) => void) | undefined;
    }) => Promise<Uint8Array | undefined>;
    getText: (url: string, init?: RequestInit | undefined) => Promise<[any, undefined] | [null, string]>;
    cache: (url: string, cache?: RequestCache) => Promise<[any, undefined] | [null, boolean]>;
    Fetch: typeof Fetch;
};
export default _default;