System.Security.Util.XMLUtil.CreateCodeGroup C# (CSharp) Method

        CreateCodeGroup (SecurityElement el)
        {
            if (el == null || !el.Tag.Equals("CodeGroup"))
                throw new ArgumentException( String.Format( CultureInfo.CurrentCulture, Environment.GetResourceString( "Argument_WrongElementType" ), "<CodeGroup>" ) ) ;
    
            String className;
            int classNameLength;
            int classNameStart;

            if (!ParseElementForObjectCreation( el,
                                                BuiltInCodeGroup,
                                                out className,
                                                out classNameStart,
                                                out classNameLength ))
            {
                goto USEREFLECTION;
            }
    
            switch (classNameLength)
            {
                case 12:
                    // NetCodeGroup
                    if (String.Compare(className, classNameStart, "NetCodeGroup", 0, classNameLength, StringComparison.Ordinal) == 0)
                        return new NetCodeGroup();
                    else
                        goto USEREFLECTION;

                case 13:
                    // FileCodeGroup
                    if (String.Compare(className, classNameStart, "FileCodeGroup", 0, classNameLength, StringComparison.Ordinal) == 0)
                        return new FileCodeGroup();
                    else
                        goto USEREFLECTION;
                case 14:
                    // UnionCodeGroup
                    if (String.Compare(className, classNameStart, "UnionCodeGroup", 0, classNameLength, StringComparison.Ordinal) == 0)
                        return new UnionCodeGroup();
                    else
                        goto USEREFLECTION;
                                
                case 19:
                    // FirstMatchCodeGroup
                    if (String.Compare(className, classNameStart, "FirstMatchCodeGroup", 0, classNameLength, StringComparison.Ordinal) == 0)
                        return new FirstMatchCodeGroup();
                    else
                        goto USEREFLECTION;

                default:
                    goto USEREFLECTION;
            }

USEREFLECTION: 
            Type groupClass = null;
            CodeGroup group = null;

            new ReflectionPermission(ReflectionPermissionFlag.MemberAccess).Assert();
            groupClass = GetClassFromElement(el, true);
            if (groupClass == null)
                return null;
            if (!(typeof(CodeGroup).IsAssignableFrom(groupClass)))
                throw new ArgumentException( Environment.GetResourceString("Argument_NotACodeGroupType") );

            group = (CodeGroup) Activator.CreateInstance(groupClass, true);

            BCLDebug.Assert( groupClass.Module.Assembly != Assembly.GetExecutingAssembly(),
                "This path should not get called for mscorlib based classes" );

            return group;
        }