System.Xml.XmlConvert.VerifyNormalizedString C# (CSharp) Method

        internal static string VerifyNormalizedString(string str)
        {
            if (str.IndexOfAny(crt) != -1)
            {
                throw new XmlSchemaException(SR.Sch_NotNormalizedString, str);
            }
            return str;
        }