public async Task ShouldPerformPolymerReactionForSimpleExample()
        {
            var sut = new Polymer("dabAcCaCBAcCcaDA");
            await sut.ReactAsync();

            sut.Units.Should().Be(10);
        }
        public async Task ShouldPerformPolymerReactionForBigInput()
        {
            var sut = new Polymer(PuzzleInputParser.ParseString("Day5/Input.txt"));
            await sut.ReactAsync();

            sut.Units.Should().Be(10774);
        }