def test_get_paternal_grandmother(self):
member = Person(7, "alpha", "Male")
father = Person(8, "beta", "Male")
grandmother = Person(9, "charlie", "Female")
# error cases
self.assertEqual(Relations().get_paternal_grandmother(member), None)
member.father = father
self.assertEqual(Relations().get_paternal_grandmother(member), None)
member.father.mother = grandmother
self.assertEqual(Relations().get_paternal_grandmother(member), grandmother)
def test_get_paternal_grandmother(self):
child = Person(7, "alpha", "Male")
father = Person(8, "beta", "Male")
grandmother = Person(9, "charlie", "Female")
# error cases
self.assertEqual(child.get_paternal_grandmother(), None)
child.father = father
self.assertEqual(child.get_paternal_grandmother(), None)
child.father.mother = grandmother
self.assertEqual(child.get_paternal_grandmother(), grandmother)
