Django, generic relations, make fixtures

I'm trying to add generic relations and one-to-one relations support for django-test-utils makefixture command, here is the source http://github.com/ericholscher/django-test-utils/blob/master/test_utils/management/commands/makefixture.py

Does somebody have ideas how to do this? Or may be there is another tool for such thing as:

./manage.py dumpcmd User[:10] > fixtures.json