def test_breadth_four():
new_tree, expected = BinaryTree(), [2, 7, 5, 2]
new_tree.add(2)
new_tree.add(7)
new_tree.add(5)
new_tree.add(2)
assert new_tree.breadth_first() == expected
def test_breadth_first():
tree = BinaryTree()
tree.add(1)
tree.add(2)
tree.add(3)
tree.add(4)
tree.add(5)
expected = [1, 2, 3, 4, 5]
actual = tree.breadth_first()
assert actual == expected
def test_breadth_first_nine():
new_tree = BinaryTree()
expected = [2, 7, 5, 2, 6, 9, 5, 11, 4]
new_tree.add(2)
new_tree.add(7)
new_tree.add(5)
new_tree.add(2)
new_tree.add(6)
new_tree.add(9)
new_tree.add(5)
new_tree.add(11)
new_tree.add(4)
assert new_tree.breadth_first() == expected
def test_breadth_first_empty():
tree = BinaryTree()
expected = []
actual = tree.breadth_first()
assert actual == expected
