def clean(self):
        start = self.cleaned_data.get("start")
        end = self.cleaned_data.get("end")
        if start > end:
            raise forms.ValidationError(_(
                u'The end time must be later than start time.'))
        return self.cleaned_data
dataset/ETHPy150Open zorna/zorna/zorna/site/forms.py/SiteAlertAdminAddForm.clean/original