public String substring(int start) {if (start >= 0 && start <= count) {if (start == count) {return "";}return new String(value, start, count - start);}throw indexAndLength(start);}
public virtual string substring(int start){if (start >= 0 && start <= count){if (start == count){return string.Empty;}return new string(value, start, count - start);}throw indexAndLength(start);}