def delete(self, doc):
        if doc.id is None:
            raise DatabaseException('Document does not have id')
        if doc.sid is None:
            try:
                rs = self.db.docs.remove({'id': doc.id}, safe=True)
                assert rs['n'] == 1
            except Exception as e:
                raise DatabaseException(e)
            return None
        doc.data = None
        return self.update(doc)
def approve(self, user_id=None, service=""):
        """
        Approve the verification attempt for user

        Valid attempt statuses when calling this method:
            `submitted`, `approved`, `denied`

        After method completes:
            status is set to `approved`
            expiry_date is set to one year from now
        """
        self.expiry_date = now() + timedelta(
            days=settings.VERIFY_STUDENT["DAYS_GOOD_FOR"]
        )
        super(SoftwareSecurePhotoVerification, self).approve(user_id, service)