title: A yielded value of type 'Stream<LocationData>' must be assignable to 'LocationData'
body: <p>I was trying to make a stream function that returns <code>LocationData</code> as stream.
  But I got this error saying</p>
  <p><code>A yielded value of type 'Stream&lt;LocationData&gt;' must be assignable to 'LocationData'</code></p>
  <pre><code>Stream&lt;LocationData&gt;  getCoordinates() async* {
        yield Location.instance.onLocationChanged;//error shows here
  }
  </code></pre>