import { RouteReuseStrategy , ActivatedRouteSnapshot , DetachedRouteHandle } from '@angular/router' ; export abstract class BaseRouteReuseStrategy implements RouteReuseStrategy { /**
     * Whether the given route should detach for later reuse.
     * Always returns false for `BaseRouteReuseStrategy`.
     * */ shouldDetach ( route ) { return false ; } /**
     * A no-op; the route is never stored since this strategy never detaches routes for later re-use.
     */ store ( route , detachedTree ) { } /** Returns `false`, meaning the route (and its subtree) is never reattached */ shouldAttach ( route ) { return false ; } /** Returns `null` because this strategy does not store routes for later re-use. */ retrieve ( route ) { return null ; } /**
     * Determines if a route should be reused.
     * This strategy returns `true` when the future route config and current route config are
     * identical.
     */ shouldReuseRoute ( future , curr ) { return future . routeConfig === curr . routeConfig ; } } export class DefaultRouteReuseStrategy extends BaseRouteReuseStrategy { }