title: Type 'Subscription' is missing the following properties
body: <p>IDE shows error when I write this code.</p>
  
  <p>I have a component that calls service in ngOnInit to get the data. Service calls the other service to get some data and use it to get data then returns it.</p>
  
  <p>component:</p>
  
  <pre><code>ngOnInit() {
      const token = "abc";
      this.service.getContactPersons(token).subscribe(
        persons =&gt; this.contactPersons = persons
      );
  
    }
  </code></pre>
  
  <p>service:</p>
  
  <pre><code>getContactPersons(token: string): Observable&lt;ContactPerson[]&gt; {
  return this.tokenService.getParameters(token).pipe(
        switchMap((data: Params) =&gt; {
          return this.http.get&lt;Properties&gt;(
            this.baseUrl + `/abc/${data.param1}/properties/${data.param2}`
          );
        })
      ).subscribe((data: Properties) =&gt; data.contactPersons);
  }
  </code></pre>
  
  <p>I've got this error: "Type 'Subscription' is missing the following properties from type 'Observable': _isScalar, source, operator, lift, and 6 more."</p>