public async Task <ActionResult <long> > GetAuthorsCount(CancellationToken cancellationToken = default)
 {
     return(await _memoryCache.GetOrCreateAsync($"{nameof(AuthorsController)}_{nameof(GetAuthorsCount)}", async (entry) =>
     {
         entry.SlidingExpiration = System.TimeSpan.FromHours(1);
         return await _contentRepository.CountAuthorsAsync(cancellationToken);
     }));
 }