public Cocktail Get(int id)
        {
            var entity = _dataContext.Cocktails
                         .Include(c => c.CocktailBitters)
                         .SingleOrDefault(c => c.CocktailId == id);

            return(entity == null ? null : CocktailEntity.Map(entity));
        }
        public Cocktail Add(Cocktail model)
        {
            var entity      = CocktailEntity.Map(model);
            var newCocktail = _dataContext.Cocktails.Add(entity).Entity;

            _dataContext.SaveChanges();
            return(CocktailEntity.Map(newCocktail));
        }