public override string ToString() {
StringBuilder sb = new StringBuilder("CqlResult(");
sb.Append("Type: ");
sb.Append(Type);
sb.Append(",Rows: ");
sb.Append(Rows);
sb.Append(",Num: ");
sb.Append(Num);
sb.Append(",Schema: ");
sb.Append(Schema== null ? "<null>" : Schema.ToString());
sb.Append(")");
return sb.ToString();
}