def test_08_lca(self):
     self.assertEqual(lca(self.head2, 3, 0), None)
 def test_06_lca(self):
     self.assertEqual(lca(self.head2, 3, 3), 3)
 def test_07_lca(self):
     self.assertEqual(lca(self.head2, 8, 7), 1)
 def test_05_lca(self):
     self.assertEqual(lca(self.head2, 4, 7), 5)
 def test_04_lca(self):
     self.assertEqual(lca(self.head1, 0, 5), 0)
 def test_03_lca(self):
     self.assertEqual(lca(self.head1, 1, 4), 1)
 def test_02_lca(self):
     self.assertEqual(lca(self.head1, 3, 1), 1)
 def test_01_lca(self):
     self.assertEqual(lca(self.head1, 1, 5), 0)