import {ConnectedOverlayDirective, OverlayOrigin} from '@angular/cdk/overlay';
import {ObserveContent} from '@angular/cdk/observers';
import {FocusTrapDirective} from '@angular/cdk/a11y';

const a = new ConnectedOverlayDirective();
const b = new OverlayOrigin();
const c = new ObserveContent();
const d = new FocusTrapDirective();