import { Duplexify } from 'duplexify';
import stream from 'stream';
import { AnyFunction, TT$ } from '@upradata/util';
declare type Return<S extends AnyFunction> = ReturnType<S> extends Promise<any> ? Promise<Duplexify> : Duplexify;
export declare const duplex: <S extends (source: stream.Transform) => TT$<stream.Readable>>(stream: S) => Return<S>;
export {};