Open developer console to see activity, first create signal, paste in another browser to receive signal and paste it's output back here to receive signal and finish the connections.
<hr />
<form><textarea name="signals" rows=20 style="width:100%"></textarea><br />
<input type="button" value="create signal" />
<input type="button" value="receive signal" onclick="sigin()">
</form>
<script src="bundle.js"></script>