public void ReturnTrueIfNumberIsDivisibleByThree()
        {
            var calculator = new Calculator();
            var isDivisibleByThree = calculator.IsDivisibleByThree(9);

            Assert.IsTrue(isDivisibleByThree);
        }
        public void ReturnFalseIfNumberIsNotDivisibleByThree()
        {
            var calculator = new Calculator();
            var isDivisibleByThree = calculator.IsDivisibleByThree(4);

            Assert.IsFalse(isDivisibleByThree);
        }