title: Jasmine test doesn't reach subscribe
body: <p>I am trying to write unit test in Jasmine and I have issues with testing the subscribe after the dialog opens. My test looks like this:</p>
  <pre><code>it('should open pop up', () =&gt; {
      const openDialogSpy = spyOn(component.dialog, 'open').and.returnValue({
          afterClosed: () =&gt; of(false)
      });
  
      component.onClickNewUser();
  
      const parameters= {
          id: 0,
          name: 'banana'
      };
  
      expect(openDialogSpy).toHaveBeenCalled();
      expect(component.dialog.open).toHaveBeenCalledWith(
          AddUserDialogComponent,
          {
              data: parameters 
          }
      );
  });
  </code></pre>
  <p>And it passes and everything is okay. But when I run code coverage I see that it didn't reach the subscribe <a href="https://i.stack.imgur.com/dZRQT.jpg" rel="nofollow noreferrer">code coverage image</a></p>
  <p>Is there a way for me to test this part as well??</p>