def as_hidden(self, attrs=None):
        return self.as_widget(self.field.hidden_widget(), attrs)
Used by ``stringify`` within validate, to turn non-string values
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-0.96/django/newforms/forms.py/BoundField.as_hidden--crossover with--dataset/ETHPy150Open boakley/robotframework-workbench/rwb/lib/configobj.py/ConfigObj._str