def skip(self, end_time=None):
        end_time = end_time or timezone.now()
        self.skipped = True
        self.save(update_fields=('skipped', 'skipped_end_time'))
Called by QCombination objects.
dataset/ETHPy150Open mozilla/pontoon/pontoon/sync/models.py/ProjectSyncLog.skip--crossover with--dataset/ETHPy150Open MongoEngine/mongoengine/mongoengine/queryset/visitor.py/QNodeVisitor.visit_combination