def non_field_errors(self):
        return self.errors.get(NON_FIELD_ERRORS, self.error_class())
:type build: Build
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.2/django/forms/forms.py/BaseForm.non_field_errors--crossover with--dataset/ETHPy150Open box/ClusterRunner/app/master/build_scheduler.py/BuildScheduler.__init__