public void PartTwoTest()
        {
            // Arrange
            var target = new Day21();

            // Act
            var result = target.Debug(Part.Two);

            // Assert
            Assert.IsNotNull(result);
            Assert.AreEqual("aghfcdeb", result);
        }
        public void PartOneTest()
        {
            // Arrange
            var target = new Day21();

            // Act
            var result = target.Debug(Part.One);

            // Assert
            Assert.IsNotNull(result);
            Assert.AreEqual("dbfgaehc", result);
        }