: #0070C1">observer</span><span style="color: #000000">: </span><span style="color: #267F99">AudioVideoObserver</span><span style="color: #000000"> = {</span>
<span style="color: #000000">      </span><span style="color: #795E26">remoteVideoSourcesDidChange</span><span style="color: #001080">:</span><span style="color: #000000"> (</span><span style="color: #001080">videoSources</span><span style="color: #000000">: </span><span style="color: #267F99">VideoSource</span><span style="color: #000000">[]): </span