def test_remove(self) -> None:
        t = self._get_binary_search_tree()

        t.remove(13)
        assert t.root is not None
        assert t.root.right is not None
        assert t.root.right.right is not None
        assert t.root.right.right.right is None
        assert t.root.right.right.left is None

        t.remove(7)
        assert t.root.left is not None
        assert t.root.left.right is not None
        assert t.root.left.right.left is not None
        assert t.root.left.right.right is None
        assert t.root.left.right.left.label == 4

        t.remove(6)
        assert t.root.left.left is not None
        assert t.root.left.right.right is not None
        assert t.root.left.left.label == 1
        assert t.root.left.right.label == 4
        assert t.root.left.right.right.label == 5
        assert t.root.left.right.left is None
        assert t.root.left.left.parent == t.root.left
        assert t.root.left.right.parent == t.root.left

        t.remove(3)
        assert t.root is not None
        assert t.root.left.label == 4
        assert t.root.left.right.label == 5
        assert t.root.left.left.label == 1
        assert t.root.left.parent == t.root
        assert t.root.left.left.parent == t.root.left
        assert t.root.left.right.parent == t.root.left

        t.remove(4)
        assert t.root.left is not None
        assert t.root.left.left is not None
        assert t.root.left.label == 5
        assert t.root.left.right is None
        assert t.root.left.left.label == 1
        assert t.root.left.parent == t.root
        assert t.root.left.left.parent == t.root.left