public void FibonacciShouldPrintFirstNumber()
{
FibonacciNumbers fibonacci = new FibonacciNumbers();
int expected = 1;
int actual = fibonacci.GetFirst();
Assert.AreEqual(expected, actual);
}
public void FibonacciShouldPrintNextNumber()
{
FibonacciNumbers fibonacci = new FibonacciNumbers();
BigInteger input = fibonacci.GetFirst();
BigInteger expected = 1;
BigInteger actual = fibonacci.GetNext(input);
Assert.AreEqual(expected, actual);
}