def manipulator(self):
    if self._manipulator is None:
      msg = ('MeasurementInterface.manipulator() must be implemented or a '
             '"manipulator=..." must be provided to the constructor')
      log.error(msg)
      raise Exception(msg)
    return self._manipulator
called once to create the search.manipulator.ConfigurationManipulator
dataset/ETHPy150Open jansel/opentuner/opentuner/measurement/interface.py/MeasurementInterface.manipulator