def test_update_node_count(self):
node_5 = Node(5)
node_0 = Node(0)
node_12 = Node(12)
tree = AVL(node_5)
tree._set_root(node_5)
node_5.set_left_child(node_0)
node_5.set_right_child(node_12)
node_0.set_parent(node_5)
node_12.set_parent(node_5)
node_5.set_node_count(2)
node_6 = Node(6)
node_12.set_left_child(node_6)
node_6.set_parent(node_12)
tree._update_node_counts(node_6)
expect(node_5.get_node_count()).to.be.equal(4)
expect(node_0.get_node_count()).to.be.equal(1)
expect(node_12.get_node_count()).to.be.equal(2)
expect(node_6.get_node_count()).to.be.equal(1)
