title: Angular TypeError: _this.handler.handle is not a function
body: <p>I am trying to run my tests in angular, but apparently i got an error like:</p>
  
  <pre><code>TypeError: _this.handler.handle is not a function
      at MergeMapSubscriber.project (http://localhost:9876/_karma_webpack_/webpack:/node_modules/@angular/common/esm5/http.js:1464:80)
      at MergeMapSubscriber.webpackJsonp../node_modules/rxjs/_esm5/operators/mergeMap.js.MergeMapSubscriber._tryNext (http://localhost:9876/_karma_webpack_/webpack:/node_modules/rxjs/_esm5/operators/mergeMap.js:128:1)
      at MergeMapSubscriber.webpackJsonp../node_modules/rxjs/_esm5/operators/mergeMap.js.MergeMapSubscriber._next (http://localhost:9876/_karma_webpack_/webpack:/node_modules/rxjs/_esm5/operators/mergeMap.js:118:1)
      at MergeMapSubscriber.webpackJsonp../node_modules/rxjs/_esm5/Subscriber.js.Subscriber.next (http://localhost:9876/_karma_webpack_/webpack:/node_modules/rxjs/_esm5/Subscriber.js:92:1)
      at ScalarObservable.webpackJsonp../node_modules/rxjs/_esm5/observable/ScalarObservable.js.ScalarObservable._subscribe (http://localhost:9876/_karma_webpack_/webpack:/node_modules/rxjs/_esm5/observable/ScalarObservable.js:51:1)
      at ScalarObservable.webpackJsonp../node_modules/rxjs/_esm5/Observable.js.Observable._trySubscribe (http://localhost:9876/_karma_webpack_/webpack:/node_modules/rxjs/_esm5/Observable.js:172:1)
      at ScalarObservable.webpackJsonp../node_modules/rxjs/_esm5/Observable.js.Observable.subscribe (http://localhost:9876/_karma_webpack_/webpack:/node_modules/rxjs/_esm5/Observable.js:160:1)
      at MergeMapOperator.webpackJsonp../node_modules/rxjs/_esm5/operators/mergeMap.js.MergeMapOperator.call (http://localhost:9876/_karma_webpack_/webpack:/node_modules/rxjs/_esm5/operators/mergeMap.js:92:1)
      at Observable.webpackJsonp../node_modules/rxjs/_esm5/Observable.js.Observable.subscribe (http://localhost:9876/_karma_webpack_/webpack:/node_modules/rxjs/_esm5/Observable.js:157:1)
      at FilterOperator.webpackJsonp../node_modules/rxjs/_esm5/operators/filter.js.FilterOperator.call (http://localhost:9876/_karma_webpack_/webpack:/node_modules/rxjs/_esm5/operators/filter.js:61:1)
  </code></pre>
  
  <p>I did not change anything in my tests, but in my component I did add a new import: <code>import {Router} from "@angular/router";</code> and of course in my tests i did add <code>RouterModule</code> in imports. What do I do wrong?</p>