public DirectXLinkCollector(CubeSearcher searcher, FieldDefinition fieldDef, XGroups groups) {
   super(searcher);
   this.groups = groups;
   ValueSearcher vs =
       searcher.getValueSearcher(fieldDef.getTableName(), fieldDef.getXLinkJunction());
   fieldSets = new BdLongSet[vs.size()];
   for (int i = 0; i < vs.size(); i++) {
     BSTR val = vs.getValue(i);
     BdLongSet set = groups.groupsMap.get(val);
     fieldSets[i] = set;
   }
   fs = searcher.getFieldSearcher(fieldDef.getTableName(), fieldDef.getXLinkJunction());
   iter = new IntIterator();
 }