public void AncestorTest()
{
// Passing in the top-level simulations object should return null.
Assert.Null(simulations.FindAncestor <IModel>());
// Passing in an object should never return that object
Assert.AreNotEqual(simulation, simulation.FindAncestor <Simulation>());
// Searching for any IModel ancestor should return the node's parent.
Assert.AreEqual(simulation.Parent, simulation.FindAncestor <IModel>());
}