+ Field effective_loss_ratio is specific for use in MLRsearch,
+ where measurements with lower loss ratio at higher target_tr
+ cannot be relied upon if there is a measurement with higher loss ratio
+ at lower target_tr. In this case, the higher loss ratio from
+ other measurement is stored as effective loss ratio in this measurement.
+ If None, the computed loss ratio of this measurement is used.
+ If not None, the computed ratio can still be apllied if it is larger.
+