public void MultiplyNumbersReturnsSum()
        {
            var rule = new MultiplyRule(4, 5);

            var actual = rule.Apply();

            JsonAssert.AreEquivalent(20, actual);
        }
        public void MultiplyNonNumberThrowsError()
        {
            var rule = new MultiplyRule("test", 5);

            Assert.Throws <JsonLogicException>(() => rule.Apply());
        }