def test_get_node():
cdll = CircularDoublyLinkedList()
node_1 = Node(RandomString.make())
node_2 = Node(RandomString.make())
node_3 = Node(RandomString.make())
cdll.insert_at_beg(node_1)
assert node_1 == cdll.get_node(0)
assert cdll.get_node(1) is None
cdll.insert_after(node_1, node_2)
cdll.insert_after(node_2, node_3)
assert node_2 == cdll.get_node(1)
assert node_3 == cdll.get_node(2)
assert cdll.get_node(3) is None
assert cdll.get_node(999) is None
def test_get_node_empty():
cdll = CircularDoublyLinkedList()
assert cdll.get_node(0) is None
assert cdll.get_node(1) is None
assert cdll.get_node(100) is None