import Tuple from './Tuple';
import Stream from './Stream';
import Relation from './Relation';
export default class Pipe {
    output?: Stream;
    _backlog: Tuple[];
    _doneCalled: boolean;
    next: (rel: Tuple) => void;
    done: () => void;
    sendTo(receiver: Stream): void;
    waitForAll(callback: (ts: Tuple[]) => void): void;
    sendRelationTo(out: Stream, attrName: string): void;
    take(): Tuple[];
    takeAsRelation(): Relation;
}