public BeerDTO UpdateBeer(Guid id, BeerDTO beerDto)
        {

            if (!this.context.Breweries.Any(b => b.Name == beerDto.BreweryName))
            {
                throw new InvalidOperationException(); // no brewery with this id
            }
            if (!this.context.Styles.Any(s => s.Name == beerDto.StyleName))
            {
                throw new InvalidOperationException(); // no style with this id
            }
            if (!this.context.Countries.Any(c=>c.Name == beerDto.CountryName))
            {
                throw new InvalidOperationException(); // no country with this id
            }

            var beer = this.context.Beers.Where(b => b.IsDeleted == false)
                                          .FirstOrDefault(b => b.Id == beerDto.Id) ?? throw new ArgumentNullException();

            if (this.context.Beers.Any(b => b.Name == beerDto.Name && b.Id != beerDto.Id))
            {
                throw new InvalidOperationException(); // other beer with same name already exist
            }

            beer.Name = beerDto.Name;
            beer.Brand = beerDto.Brand;
            beer.CountryId = this.countryService.GetId(beerDto.CountryName);
            beer.BreweryId = this.breweryService.GetId(beerDto.BreweryName);
            beer.StyleId = this.styleService.GetId(beerDto.StyleName);
            beer.ABV = beerDto.ABV;

            beer.UpdatedOn = this.dateTimeProvider.GetDateTime();

            this.context.Beers.Update(beer);
            this.context.SaveChanges();

            return beerDto;
        }