title: How to use static combineLatest correctly
body: <p>Since <code>RxJS</code> v.6.5, the static <code>combineLatest</code> syntax 
  <code>combined$ = combineLatest(a$,b$,c$);</code> is deprecated. </p>
  
  <p>Instead you should use following syntax:</p>
  
  <p><code>combined$ = combineLatest([a$,b$,c$])</code>;</p>
  
  <p>Where they are: <code>a$: Observable&lt;T&gt;, b$: Observable&lt;U&gt;, c$: Observable&lt;V&gt;</code></p>
  
  <p>This declaration although gives me several linting errors: </p>
  
  <blockquote>
    <p>Argument type [Observable&lt;ObservableValueOf&lt;Observable&lt;T>>>,
    Observable&lt;ObservableValueOf&lt;Observable&lt;U>>>,
    Observable&lt;ObservableValueOf&lt;Observable&lt;V>>>]  is not assignable to
    parameter type [Observable&lt;ObservableValueOf&lt;Observable&lt;T>>>]</p>
  </blockquote>
  
  <p>So, where is my error? 
  Thanks a lot.</p>