System.Xml.Serialization.XmlReflectionImporter.GetDefaultValue C# (CSharp) Method

        private object GetDefaultValue(TypeDesc fieldTypeDesc, Type t, XmlAttributes a)
        {
            if (a.XmlDefaultValue == null || a.XmlDefaultValue == DBNull.Value) return null;
            if (!(fieldTypeDesc.Kind == TypeKind.Primitive || fieldTypeDesc.Kind == TypeKind.Enum))
            {
                //throw new InvalidOperationException(SR.XmlIllegalDefault);
                a.XmlDefaultValue = null;
                return a.XmlDefaultValue;
            }
            // for enums validate and return a string representation
            if (fieldTypeDesc.Kind == TypeKind.Enum)
            {
                string strValue = Enum.Format(t, a.XmlDefaultValue, "G").Replace(",", " ");
                string numValue = Enum.Format(t, a.XmlDefaultValue, "D");
                if (strValue == numValue) // means enum value wasn't recognized
                    throw new InvalidOperationException(SR.Format(SR.XmlInvalidDefaultValue, strValue, a.XmlDefaultValue.GetType().FullName));
                return strValue;
            }
            return a.XmlDefaultValue;
        }