System.Xml.Serialization.CodeIdentifier.IsValidStart C# (CSharp) Method

        private static bool IsValidStart(char c)
        {
            // the given char is already a valid name character
#if DEBUG
            // use exception in the place of Debug.Assert to avoid throwing asserts from a server process such as aspnet_ewp.exe
            if (!IsValid(c)) throw new ArgumentException(SR.Format(SR.XmlInternalErrorDetails, "Invalid identifier character " + ((Int16)c).ToString(CultureInfo.InvariantCulture)), "c");
#endif

            // First char cannot be a number
            if (CharUnicodeInfo.GetUnicodeCategory(c) == UnicodeCategory.DecimalDigitNumber)
                return false;
            return true;
        }