this(null, null);
    }

    public ProtoLogger(@Nullable OutputStream out, @Nullable OutputStream err) {
        this.out = new PrintWriter(toPsOrDef(out, System.out), true);
        this.err = new PrintWriter(toPsOrDef(err, System.err), true);
    }

    private PrintStream toPsOrDef(OutputStream outputStream, PrintStream def) {
        if (outputStream == null) {
            return def;
        }