[dataimport] add a filter function to not fail if some extentity has several values for an attribute of final relation
the function will simply record a warning in the import log and keep a value
randomly.
Notice the function has to be explicitly inserted in the transformation stream.
.. _rset_module:
:mod:`cubicweb.rset`
====================
.. automodule:: cubicweb.rset
.. autoclass:: ResultSet
:members: