@Override
    public void write(JmeExporter ex) throws IOException {
        OutputCapsule output = ex.getCapsule(this);
        output.write(rootBones, "rootBones", null);
        output.write(boneList, "boneList", null);
    }
returns the number of bones of this skeleton
@return the count (&ge;0)
jme3-core/src/main/java/com/jme3/animation/Skeleton.java