public override string ToString()
{
StringBuilder sb = new StringBuilder("createTable_result(");
sb.Append("Io: ");
sb.Append(Io == null ? "<null>" : Io.ToString());
sb.Append(",Ia: ");
sb.Append(Ia == null ? "<null>" : Ia.ToString());
sb.Append(",Exist: ");
sb.Append(Exist == null ? "<null>" : Exist.ToString());
sb.Append(")");
return sb.ToString();
}