def test_modify_uns_in_copy():
    # https://github.com/theislab/anndata/issues/571
    adata = ad.AnnData(np.ones((5, 5)), uns={"parent": {"key": "value"}})
    adata_copy = adata[:3].copy()
    adata_copy.uns["parent"]["key"] = "new_value"
    assert adata.uns["parent"]["key"] != adata_copy.uns["parent"]["key"]
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