title: Angular 4+ send service from child to parent via interface
body: <p>I was searching for answer several hours..
  Is possible in angular to send from child to parent service via interface? </p>
  
  <ul>
  <li>parent component</li>
  <li>child component (extends parent)</li>
  <li>interface for service</li>
  <li>service (e.g. locationService) (implementing iface above)</li>
  </ul>
  
  <p><em>Child extends from Parent</em></p>
  
  <pre><code>constructor(public locationService: LocationService) {
   super(locationService);  //parent 
  }
  </code></pre>
  
  <p>And parent looks like: </p>
  
  <pre><code>constructor(generalService?: IService) {
      this.myService = generalService;
    }
  </code></pre>
  
  <p>and than I want to do something like: <code>this.myService.doLogic();</code></p>
  
  <p>I got runtime error: <strong>Error: Uncaught (in promise): Error: Can't resolve all parameters for ParentComponent: (?).</strong></p>
  
  <p>Thanks for any hint or help.. </p>