public void WhenWordDoesMatchRules_TrueIsReturned(string word)
        {
            var rule    = new LetterDuplicationRule(2, 1);
            var isValid = rule.Evaluate(word);

            Assert.True(isValid);
        }
        public void WhenWordDoesntMatchRules_FalseIsReturned()
        {
            var rule    = new LetterDuplicationRule(2, 1);
            var isValid = rule.Evaluate("bad");

            Assert.False(isValid);
        }