public override string execute(Blackfin bf, string[] args)
            {
                if (!bf.GetRegisterLabels())
                {
                    return(null);
                }

                List <string> labels = bf.RegisterLabels;
                string        result = "\nRegister Labels;\n";

                foreach (string label in labels)
                {
                    result += "\t" + label + "\n";
                }

                return(result);
            }