this(prefs, new OutputStreamWriter(os));
this.prefs = prefs; Writer w; try { w = new OutputStreamWriter(os, "UTF-8"); } catch (UnsupportedEncodingException uee) {  InternalError ie = new InternalError("UTF-8 encoding missing"); ie.initCause(uee); throw ie; } this.bw = new BufferedWriter(w);
    public NodeWriter(Preferences prefs, OutputStream os) {        this(prefs, new OutputStreamWriter(os));    }