def label_from_instance(self, obj):
    url = reverse('widgy.contrib.widgy_mezzanine.views.preview', kwargs={'node_pk': obj.working_copy.pk})
    return format_html('<a href="{url}">{preview}</a>', url=url, preview=ugettext('preview'))
def label_from_instance(self, obj):
    url = reverse('widgy.contrib.widgy_mezzanine.views.preview', kwargs={'node_pk': obj.working_copy.pk})
    return format_html('<a href="{url}">{preview}</a>', url=url, preview=ugettext('preview'))