def test_remove():
root = Node(1)
root.insert(0)
root.insert(3)
root.insert(2)
root.insert(4)
root.remove(0)
assert str(root) == "1 2 3 4"
assert root.tuple() == (None, 1, ((None, 2, None), 3, (None, 4, None)))
root.remove(2)
assert str(root) == "1 3 4"
assert root.tuple() == (None, 1, (None, 3, (None, 4, None)))
