public void ShouldReturnTheRightFibonacciNumberBasedOnIndex()
{
FibonacciSequence fibonacciSequence = new FibonacciSequence();
Assert.AreEqual(0, fibonacciSequence.GetByIndex(0));
Assert.AreEqual(1, fibonacciSequence.GetByIndex(1));
Assert.AreEqual(1, fibonacciSequence.GetByIndex(2));
Assert.AreEqual(2, fibonacciSequence.GetByIndex(3));
Assert.AreEqual(3, fibonacciSequence.GetByIndex(4));
Assert.AreEqual(5, fibonacciSequence.GetByIndex(5));
Assert.AreEqual(8, fibonacciSequence.GetByIndex(6));
Assert.AreEqual(13, fibonacciSequence.GetByIndex(7));
Assert.AreEqual(21, fibonacciSequence.GetByIndex(8));
Assert.AreEqual(34, fibonacciSequence.GetByIndex(9));
Assert.AreEqual(55, fibonacciSequence.GetByIndex(10));
Assert.AreEqual(89, fibonacciSequence.GetByIndex(11));
Assert.AreEqual(144, fibonacciSequence.GetByIndex(12));
Assert.AreEqual(233, fibonacciSequence.GetByIndex(13));
Assert.AreEqual(377, fibonacciSequence.GetByIndex(14));
Assert.AreEqual(610, fibonacciSequence.GetByIndex(15));
Assert.AreEqual(987, fibonacciSequence.GetByIndex(16));
Assert.AreEqual(1597, fibonacciSequence.GetByIndex(17));
Assert.AreEqual(2584, fibonacciSequence.GetByIndex(18));
}