def is_safe_callable(self, obj):
        return not (getattr(obj, 'unsafe_callable', False) or
                    getattr(obj, 'alters_data', False))
Default Expiry date based on the expire offset
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/jinja2-2.6/jinja2/sandbox.py/SandboxedEnvironment.is_safe_callable--crossover with--dataset/ETHPy150Open sahana/eden/modules/s3db/cap.py/S3CAPModel.cap_expirydate