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());
        }
        public void Example_2()
        {
            var ai = new AllergenIdentifier
            {
                Sets = ExampleInput.Select(x => new Set(x)).ToList()
            };

            ai.Analyze();

            var dangerousIngredients = ai.Sets
                                       .SelectMany(x => x.DangerousIngredients)
                                       .Distinct()
                                       .OrderBy(x => x.Value)
                                       .Aggregate("", (c, n) => $"{c},{n.Key}")[1..];

            Assert.Equal("mxmxvkd,sqjhc,fvjkl", dangerousIngredients);
        }