Why do you test for open?

https://github.com/goxr3plus/java-stream-player/blob/4991e4acc52041ca1529404d176c57b4171eba94/src/main/java/com/goxr3plus/streamplayer/stream/StreamPlayer.java#L529

On the line above the test, you just opened the sourceDataLine. Don't you trust that it worked?
If it didn't work, if the line wasn't opened, isn't that a reason to throw an exception, rather than silently ignore the failure?