private IEnumerable <KeyValuePair <string, string> > LoadResources(string culture, string resourceFile)
        {
            if (_resourcesCacheMode != ResourcesCacheMode.InMemory)
            {
                return(_resourcesLoadMode == ResourcesLoadMode.EmbeddedResource
                    ? LoadResourcesFromEmbeddedResources(culture, resourceFile)
                    : LoadResourcesFromFile(culture, $"{culture}.json"));
            }

            var cacheKey = _resourcesLoadMode == ResourcesLoadMode.EmbeddedResource ? resourceFile : $"{culture}.json";

            if (_jsonStringLocalizerInMemoryCache.TryGet(cacheKey, out var data))
            {
                return(data);
            }

            return(_jsonStringLocalizerInMemoryCache.AddAndGet(cacheKey,
                                                               _resourcesLoadMode == ResourcesLoadMode.EmbeddedResource
                    ? LoadResourcesFromEmbeddedResources(culture, resourceFile)
                    : LoadResourcesFromFile(culture, $"{culture}.json")));
        }