def append(self, data):
    data_length = len(data)
    if self._size + data_length > self._flush_size:
      self.flush()

    if not self._exclusive and data_length > _FILES_API_MAX_SIZE:
      raise errors.Error(
          "Too big input %s (%s)."  % (data_length, _FILES_API_MAX_SIZE))
    else:
      self._buffer.append(data)
      self._size += data_length

    if self._size > self._flush_size:
      self.flush()
Return user keypairs list.
dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/ext/mapreduce/output_writers.py/RecordsPool.append--crossover with--dataset/ETHPy150Open openstack/rally/rally/plugins/openstack/scenarios/nova/utils.py/NovaScenario._list_keypairs