code: public IceMediaStream getMediaStream(String streamName) {
  		IceMediaStream mediaStream;
  		synchronized (mediaStreams) {
  			mediaStream = this.mediaStreams.get(streamName);
  		}
  		return mediaStream;
  	}
docs: Gets a media stream by name
  
  @param streamName
  The name of the media stream
  @return The media stream. Returns null, if no media stream exists with
  such name.