public RbacEncryptedColumns(string metaDataXml)
        {
            RbacEncryptedColumns cols = FromXml(metaDataXml);

            foreach (RbacEncryptedColumn col in cols)
            {
                this.Add(col);
            }
        }
        public static RbacEncryptedColumns FromXml(string metaDataxml)
        {
            RbacEncryptedColumns cols = new RbacEncryptedColumns();
            XmlDocument          doc  = new XmlDocument();

            doc.LoadXml(metaDataxml);

            foreach (XmlNode encColumn in doc.DocumentElement.ChildNodes)
            {
                if (encColumn.NodeType == XmlNodeType.Comment)
                {
                    continue;
                }

                cols.Add(new RbacEncryptedColumn(encColumn.Attributes["ColumnName"].Value, encColumn.Attributes["TableName"].Value));
            }
            return(cols);
        }