public MenuGroupsViewModel(List <FoodItem> foodItems)
        {
            MenuGroups = new List <MenuGroup>();

            var groupsNames = foodItems.Select(mi => mi.Category).Distinct().OrderBy(mi => mi);

            foreach (var groupName in groupsNames)
            {
                var foodItemsInGroup = foodItems.Where(t => t.Category == groupName);
                var newGroup         = new MenuGroup()
                {
                    Title      = groupName == null ? "Brak" : groupName,
                    ShortTitle = groupName == null ? "Brak" : groupName,
                };
                newGroup.AddRange(foodItemsInGroup);
                MenuGroups.Add(newGroup);
            }
        }