public void PasswordIsInvalidForPolicyWithNoOccurrences()
        {
            const string policyAndPassword  = "******";
            var          rentalShopPassword = new RentalShopPassword(policyAndPassword);

            Assert.IsFalse(rentalShopPassword.IsValid);
        }
        public void PasswordIsInvalidForPolicyWithBothOccurrences()
        {
            const string policyAndPassword  = "******";
            var          rentalShopPassword = new RentalShopPassword(policyAndPassword);

            Assert.IsFalse(rentalShopPassword.IsValid);
        }
        public void PasswordIsValidForPolicyWithOneOccurrence()
        {
            const string policyAndPassword  = "******";
            var          rentalShopPassword = new RentalShopPassword(policyAndPassword);

            Assert.IsTrue(rentalShopPassword.IsValid);
        }