def test_succ(self):
import random
random.seed(7477)
entries = get_random_entries()
tree = AVLTree(entries)
rev_entries = sorted(entries, reverse=True)
with self.subTest(f"test succ found"):
succ, prev = None, None
for entry in rev_entries:
try:
succ = tree.succ(entry)
except KeyError:
self.assertIsNone(prev)
self.assertEqual(prev, succ)
prev = entry
with self.assertRaises(KeyError) as context:
tree.succ(1000000)
self.assertIn("Successor of 1000000 not found.",
str(context.exception))
