NPE in MediaDescription#setAttribute() because CandidateAttribute#attribute is null

[GoogleCodeExporter]

What steps will reproduce the problem?
- Create Agent and add audio stream, likle in test/ICE.java
- call IceSdpUtils#initSessionDescription()
- get 1st MediaDescription from new SessionDescription
- call MediaDescription.setAttribute("foo", "bar");

    Exception in thread "main" java.lang.NullPointerException
        at gov.nist.javax.sdp.MediaDescriptionImpl.setAttribute(MediaDescriptionImpl.java:505)

What version of the product are you using? On what operating system?
r360

Original issue reported on code.google.com by [email protected] on 5 Nov 2013 at 1:13