public void Execute_AncestorsAboveSourceAreMarked()
{
var alg = new FindBasicRelationships();
alg.Execute(tree, roxi);
Assert.IsTrue(brent.HasFact(FactType.Ancestor));
Assert.IsTrue(greg.HasFact(FactType.Ancestor));
Assert.IsTrue(pam.HasFact(FactType.Ancestor));
}