def test_balance_right():
"""Test that a right side is larger and returns a negative int."""
from bst import Node
a = Node(20)
a.right = Node(23)
assert a.balance() == -1
def test_balance_one():
"""Test that a node of one returns a depth of one."""
from bst import Node
a = Node(1)
assert a.balance() == 0
def test_balance_left():
"""Test that a left side is larger and returns a positive int."""
from bst import Node
a = Node(20)
a.left = Node(18)
assert a.balance() == 1
def test_balance_none():
"""Test that a node of nothing returns a value of nothing."""
from bst import Node
a = Node()
assert a.balance() == 0
