def get_type_and_value(self, field_name):
        fields = self.list_fields_and_values([field_name])
        if not fields:
            return None
        field_name, value_type, value = fields[0]
        return value_type, value
Calls the request-endcallback that the app may have set
dataset/ETHPy150Open cloudera/hue/desktop/core/ext-py/tablib-0.10.0/tablib/packages/odf3/userfield.py/UserFields.get_type_and_value--crossover with--dataset/ETHPy150Open GoogleCloudPlatform/python-compat-runtime/appengine-vmruntime/vmruntime/middleware.py/callback_middleware