Apply an ordered set of calibrators for the specified parameter.
        This replaces existing calibrators (if any).

        Each calibrator may have a context, which indicates when it its
        effects may be applied. Only the first matching calibrator is
        applied.

        A calibrator with context ``None`` is the *default* calibrator.
        There can be only one such calibrator, and is always applied at
        the end when no other contextual calibrator was applicable.

        :param str parameter: Either a fully-qualified XTCE name or an alias
                              in the format ``NAMESPACE/NAME``.
        :param .Calibrator[] calibrators: List of calibrators (either contextual or not)

def set_calibrators(self, parameter, calibrators):
        """
        Apply an ordered set of calibrators for the specified parameter.
        This replaces existing calibrators (if any).

        Each calibrator may have a context, which indicates when it its
        effects may be applied. Only the first matching calibrator is
        applied.

        A calibrator with context ``None`` is the *default* calibrator.
        There can be only one such calibrator, and is always applied at
        the end when no other contextual calibrator was applicable.

        :param str parameter: Either a fully-qualified XTCE name or an alias
                              in the format ``NAMESPACE/NAME``.
        :param .Calibrator[] calibrators: List of calibrators (either contextual or not)
        """
        req = mdb_pb2.ChangeParameterRequest()
        req.action = mdb_pb2.ChangeParameterRequest.SET_CALIBRATORS
        for c in calibrators:
            if c.context :
                context_calib = req.contextCalibrator.add()
                context_calib.context = rs.context
                calib_info = context_calib.calibrator
            else :                
                calib_info = req.defaultCalibrator
            
            _add_calib(calib_info, c.type, c.data)
            
            
        url = '/mdb/{}/{}/parameters/{}'.format(
            self._instance, self._processor, parameter)
        response = self._client.post_proto(url, data=req.SerializeToString())
        pti = mdb_pb2.ParameterTypeInfo()