public static Dictionary <Tag, int> GetTagsWithOccurences(List <Beer> beers)
{
BeerRepository br = new BeerRepository();
List <Tag> listOfTags = new List <Tag>();
listOfTags.AddRange(br.RetrieveTagsFromBeers(beers));
var groups = listOfTags.GroupBy(s => s)
.Select(s => new { Tag = s.Key, Count = s.Count() });
return(groups.ToDictionary(g => g.Tag, g => g.Count));
}