Set up a chain with a preselection
Preselection is done before sending jets to the FastReducer algorithm. Preselection is performed by using a ConditionFilter attribute of TrigJetHypoToolHelperNoGrouper.
When acting as a preselector the Filter instance is supplied by a sequence of Conditions. The sequence is used to select jets in the veto region. A ConditionInverter object inverts the result, and the Filter acts to veto jets satisifying all the conditions.
In the case dealt with in this merge request, an example chain has been added to the LS2_v1.py menu that species an eta-phi region.mFor this chain, the filter is set up to veto incoming jets that lie in this region.