public void CalculateIndexOfLastThousandTests()
{
// Arrange
// Act
var seventhWord = converterHelper.CalculateIndexOfLastThousand(
new string[] { "one", "million", "one", "hundred", "and", "twenty", "thousand", "and", "two" });
var notFound = converterHelper.CalculateIndexOfLastThousand(new string[] { "one", "hundred" });
// Assert
Assert.AreEqual(6, seventhWord);
Assert.AreEqual(-1, notFound);
}