public String toString() {
            try {
                StringBuilder sb = new StringBuilder();
                sb.append(String.format("%,d", getStartTimestamp()));
                if (getStep() > 0) {
                    sb.append(String.format("#%02d", getStep()));
                }
                sb.append("<" + TransactionStatus.tcString(_commitTimestamp) + ">");
                sb.append(":");
                sb.append(_value);
                return sb.toString();
            } catch (Exception e) {
                e.printStackTrace();
                return e.toString();
            }
        }