public async Task <ContainerDocumentCacheEntry <T> > GetAsync <T>(string key, CancellationToken token)
            where T : class, IContainerDocument, new()
        {
            var json = await cache
                       .GetStringAsync(key, token)
                       .ConfigureAwait(false);

            return(ContainerDocumentCacheEntry <T> .Deserialize(json));
        }