def yaml(self):
        return yaml.dump(self.serialized, default_flow_style=False,
                         encoding=None)
def _get_path(self, prefix, override_receipt_id=None):
        """
        Returns the path to a resource with this instance's `receipt_id`.

        If `override_receipt_id` is given, the path to that resource will be
        retrieved instead. This allows us to retrieve images submitted in
        previous attempts (used for reverification, where we send a new face
        photo with the same photo ID from a previous attempt).
        """
        receipt_id = self.receipt_id if override_receipt_id is None else override_receipt_id
        return os.path.join(prefix, receipt_id)