@Override
    public void write(JmeExporter ex) throws IOException {
        OutputCapsule out = ex.getCapsule(this);
        out.write(audio, "audio", null);
        out.write(length, "length", 0);
        out.write(startOffset, "startOffset", 0);
    }
Internal use only serialization

@param ex exporter
@throws IOException exception
jme3-core/src/main/java/com/jme3/animation/AudioTrack.java