def clean(self):
        if (self.data.get("tag-newtag") and
                not (self.user and self.user.has_perm("tags.manage_tags"))):
            raise forms.ValidationError(
                "You do not have permission to create new tags.")
        return self.cleaned_data
Starts a backend.
dataset/ETHPy150Open mozilla/moztrap/moztrap/view/manage/cases/forms.py/BaseCaseForm.clean--crossover with--dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/tools/appcfg.py/AppCfgApp.BackendsStart