ServiceStack.MimeTypes.GetExtension C# (CSharp) Метод

        public static string GetExtension(string mimeType)
        {
            switch (mimeType)
            {
                case ProtoBuf:
                    return ".pbuf";
            }

            var parts = mimeType.Split('/');
            if (parts.Length == 1) return "." + parts[0];
            if (parts.Length == 2) return "." + parts[1];

            throw new NotSupportedException("Unknown mimeType: " + mimeType);
        }

        public override async Task ExecuteAsync(IRequest req, IResponse res, object requestDto)
        {
            if (req.Verb != HttpMethods.Get && req.Verb != HttpMethods.Head)
            {
                return;
            }
            if (req.IsInProcessRequest())
            {
                return;
            }

            var feature = HostContext.GetPlugin <HttpCacheFeature>();

            if (feature == null)
            {
                throw new NotSupportedException(ErrorMessages.CacheFeatureMustBeEnabled.LocalizeFmt(req, "[CacheResponse]"));
            }
            if (feature.DisableCaching)
            {
                return;
            }

            var keyBase   = "res:" + req.RawUrl;
            var keySuffix = MimeTypes.GetExtension(req.ResponseContentType);

            var modifiers = "";

            if (req.ResponseContentType == MimeTypes.Json)
            {
                string jsonp = req.GetJsonpCallback();
                if (jsonp != null)
                {
                    modifiers = "jsonp:" + jsonp.SafeVarName();
                }
            }

            if (VaryByUser)
            {
                modifiers += (modifiers.Length > 0 ? "+" : "") + "user:" + req.GetSessionId();
            }

            if (VaryByRoles is { Length : > 0 })