public void Exponential()
{
IDelayStrategy strategy = new ExponentialDelayStrategy(TimeSpan.FromMilliseconds(100));
Assert.AreEqual(TimeSpan.FromMilliseconds(100), strategy.NextDelay());
Assert.AreEqual(TimeSpan.FromMilliseconds(200), strategy.NextDelay());
Assert.AreEqual(TimeSpan.FromMilliseconds(400), strategy.NextDelay());
Assert.AreEqual(TimeSpan.FromMilliseconds(800), strategy.NextDelay());
}