Detecting whether a stream has audio or video

You can check the hasAudio() and hasVideo() methods of a Stream object to see if it has audio or video

For example, when you subscribe to a stream, you may want to adjust the user interface based on whether the stream has audio or video. For example, you may want to indicate to the user whether a stream has audio or not; or you may not want to display a subscriber's view if a stream does not have video.