def attach(self, payload):
        if self._payload is None:
            self._payload = [payload]
        else:
            self._payload.append(payload)
Determine whether row can be assumed as having values.
dataset/ETHPy150Open babble/babble/include/jython/Lib/email/message.py/Message.attach--crossover with--dataset/ETHPy150Open openstack/rally/rally/task/processing/charts.py/Table._row_has_results