public void HasNoDuplicate_Alphacodes()
 {
     foreach (var currency in currencies.GetAll())
     {
         try
         {
             currencies.Get(currency.CodeAlpha);
         }
         catch (Exception)
         {
             throw new Exception($"Duplicate detected for {currency.CodeAlpha}");
         }
     }
 }
 [InlineData("fjd", "alala", false)] // not even a currency
 public void Is(string currencyCode, string isParam, bool expected)
 {
     Assert.Equal(expected, currencies.Get(currencyCode).Is(isParam));
 }