public void IsAncestorOf_Child_ReturnsTrue() { IPopUpConstArg arg = CreateMockArg(); TestPopUp popUp = new TestPopUp(arg); IPopUp childPopUp = Substitute.For <IPopUp>(); childPopUp.GetProximateParentPopUp().Returns(popUp); Assert.That(popUp.IsAncestorOf(childPopUp), Is.True); }