def test_pre_order_more():
tree = BinarySearchTree()
tree.add(20)
tree.add(5)
tree.add(10)
tree.add(15)
tree.add(25)
tree.add(35)
tree.add(40)
tree.add(23)
tree.add(45)
# assert tree._root.value == 5
# assert not tree._root.left
# assert tree._root.right.value == 10
# assert not tree._root.right.left
# assert tree._root.right.right.value == 15
# assert not tree._root.right.right.left
# assert tree._root.right.right.right.value == 20
# assert not tree._root.right.right.right.left
expected = [20, 5, 10, 15, 25, 23, 35, 40, 45]
actual = tree.pre_order()
assert actual == expected
def test_pre_order_three():
tree = BinarySearchTree()
tree.add(5)
tree.add(3)
tree.add(15)
expected = [5, 3, 15]
actual = tree.pre_order()
assert actual == expected
