1"""Convert notebook to the v1 format."""
2
3#-----------------------------------------------------------------------------
4#  Copyright (C) 2008-2011  The IPython Development Team
5#
6#  Distributed under the terms of the BSD License.  The full license is in
7#  the file COPYING, distributed as part of this software.
8#-----------------------------------------------------------------------------
9
10#-----------------------------------------------------------------------------
11# Code
12#-----------------------------------------------------------------------------
13
14def upgrade(nb, orig_version=None):
15    raise ValueError('Cannot convert to v1 notebook format')
16
17