@Override
public void computeClusters(Engine engine) {
BinningRowVisitor visitor = new BinningRowVisitor(_keyer,_config);
FilteredRows filteredRows = engine.getAllFilteredRows();
filteredRows.accept(_project, visitor);
Map<String,Map<String,Integer>> map = visitor.getMap();
_clusters = new ArrayList<Map<String,Integer>>(map.values());
Collections.sort(_clusters, new SizeComparator());
}