def test_isBalanced(self):
solution = Solution()
cases = [[[3, 9, 20, None, None, 15, 7], True],
[[1, 2, 2, 3, 3, None, None, 4, 4], False]]
for nums, expected in cases:
solution.insert(root, nums)
print(root.val)
print(root.left.val)
print(root.right.val)
print(root.left.left.val)
print(root.left.right.val)
print(root.right.left.val)
print(root.right.right.val)
solution.insert(root, nums)
assert solution.isBalanced(root) == expected
