[python] take care to this detail of @contextmanager: if an unhandled exception occurs in the block, it is reraised inside the generator at the point where the yield occurred
"""this contains the cube-specific entities' classes
:organization: Logilab
:copyright: 2001-2010 LOGILAB S.A. (Paris, FRANCE), license is LGPL v2.
:contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr
:license: GNU Lesser General Public License, v2.1 - http://www.gnu.org/licenses
"""