/// <reference types="node" />
declare type ResponseType = 'buffer' | 'json' | 'text';
declare type DataType<T extends ResponseType> = T extends 'buffer' ? Buffer : T extends 'json' ? unknown : T extends 'text' ? string : never;
export declare type UpstreamResponse<T extends ResponseType> = {
    data: DataType<T>;
    etag?: string;
};
export declare class UpstreamRequestsManager {
    private inflight;
    private pending;
    allSettled(): Promise<void>;
    getUpstream<ResType extends ResponseType>({ url, etag, responseType, }: {
        url: string;
        etag?: string;
        responseType: ResType;
    }): Promise<UpstreamResponse<ResType>>;
}
export {};