public void CalculateIndexOfBillionTests()
{
// Arrange
// Act
var secondWord = converterHelper.CalculateIndexOfBillion(new string[] { "one", "billion" });
var notFound = converterHelper.CalculateIndexOfBillion(new string[] { "one", "hundred", "thousand" });
// Assert
Assert.AreEqual(1, secondWord);
Assert.AreEqual(-1, notFound);
}