def test_find_should_return_none_for_nonexistent_value(self):
search_value = 5
rbt = RedBlackTree()
for x in [7, 11, 19, 10]:
rbt.insert(x)
self.assertTrue(rbt.search(search_value) is None)
def test_find_should_work_for_existing_value(self):
search_value = 9
rbt = RedBlackTree()
for x in [7, 11, 19, 10, search_value]:
rbt.insert(x)
self.assertTrue(rbt.search(search_value))