public void Numbers_containing_7_as_a_prime_factor_give_plong(int number)
 {
     Assert.That(Raindrops.Convert(number), Is.EqualTo("Plong"));
 }
 public string Numbers_containing_multiple_prime_factors_give_all_results_concatenated(int number)
 {
     return(Raindrops.Convert(number));
 }
 public string Non_primes_pass_through(int number)
 {
     return(Raindrops.Convert(number));
 }