import { START, DATA, END, Callbag } from 'callbag';
export declare type MsgType = START | DATA | END;
export declare type Talkback = (type: END, error?: any) => void;
export declare function isCallbag<I, O>(f: any): f is Callbag<I, O>;
export declare function isStart(msg: MsgType): msg is START;
export declare function isData(msg: MsgType): msg is DATA;
export declare function isEnd(msg: MsgType): msg is END;