-import { Operator } from '../Operator';
-import { Observable } from '../Observable';
-import { Subscriber } from '../Subscriber';
-import { Subscription } from '../Subscription';
-import { OuterSubscriber } from '../OuterSubscriber';
-import { InnerSubscriber } from '../InnerSubscriber';
-import { subscribeToResult } from '../util/subscribeToResult';
import { ObservableInput, OperatorFunction } from '../types';
import { switchMap } from './switchMap';