public void Puzzle_21A()
        {
            var ai = new AllergenIdentifier
            {
                Sets = PuzzleInput.Select(x => new Set(x)).ToList()
            };

            ai.Analyze();

            Assert.Equal(2317, ai.CountAllergenFreeIngredientsOccurrences());
        }
        public void Example_1()
        {
            var ai = new AllergenIdentifier
            {
                Sets = ExampleInput.Select(x => new Set(x)).ToList()
            };

            ai.Analyze();

            Assert.Equal(4, ai.AllergenFreeIngredients.Count);
            Assert.Equal(5, ai.CountAllergenFreeIngredientsOccurrences());
        }