public void SeekTest()
{
TestAnimation animation = new TestAnimation();
((IAnimation)animation).OnStarted();
animation.Seek(TimeSpan.FromSeconds(4.5f));
Assert.AreEqual <AnimationState>(AnimationState.Playing, animation.State);
Assert.AreEqual <TimeSpan>(TimeSpan.FromSeconds(4.5), animation.Position);
animation.Seek(2);
Assert.AreEqual <AnimationState>(AnimationState.Playing, animation.State);
Assert.AreEqual <TimeSpan>(TimeSpan.FromSeconds(2), animation.Position);
animation.Update(3);
Assert.AreNotEqual <AnimationState>(AnimationState.Playing, animation.State);
animation.StartupDirection = AnimationDirection.Backward;
((IAnimation)animation).OnStarted();
animation.Seek(1);
Assert.AreEqual <AnimationState>(AnimationState.Playing, animation.State);
animation.Update(1.001f);
Assert.AreNotEqual <AnimationState>(AnimationState.Playing, animation.State);
}