def count_trackbacks_handler(sender, **kwargs):
    entry = kwargs['entry']
    entry.trackback_count = F('trackback_count') + 1
    entry.save(update_fields=['trackback_count'])
Doesn't work. See `20110914`.
dataset/ETHPy150Open Fantomas42/django-blog-zinnia/zinnia/signals.py/count_trackbacks_handler--crossover with--dataset/ETHPy150Open lsaffre/lino/lino/utils/__init__.py/call_optional_super