public void PassDivisibleBy2And3And5And7GetCoconutFizzBuzzBanana()
{
var fizzBuzz = new FizzBuzzer();
fizzBuzz.AddRule(2, "Coconut");
fizzBuzz.AddRule(7, "Banana");
var result = fizzBuzz.ToString(210);
Assert.AreEqual("Coconut Fizz Buzz Banana", result);
}