def test_view_failed_delitem(attr):
    adata = gen_adata((10, 10))
    view = adata[5:7, :][:, :5]
    adata_hash = joblib.hash(adata)
    view_hash = joblib.hash(view)

    with pytest.raises(KeyError):
        getattr(view, attr).__delitem__("not a key")

    assert view.is_view
    assert adata_hash == joblib.hash(adata)
    assert view_hash == joblib.hash(view)
def merge(left, right):
    if left is None:
        return right
    if right is None:
        return left
    if left.prio > right.prio:
        left.right = merge(left.right, right)
        left.update()
        return left
    else:
        right.left = merge(left, right.left)
        right.update()
        return right