import { Observable } from "rxjs";
import { Match } from "../match";
import { SubscriptionRef } from "../subscription-ref";
import { BasePlugin } from "./plugin";
export declare class LetPlugin extends BasePlugin {
    private match_;
    private select_;
    constructor(match: Match, select: (source: Observable<any>) => Observable<any>, { complete }?: {
        complete?: boolean;
    });
    select(ref: SubscriptionRef): ((source: Observable<any>) => Observable<any>) | undefined;
}