public static void collateColumns(ColumnFamily returnCF, List<? extends Iterator<Cell>> toCollate, IDiskAtomFilter filter, DecoratedKey key, int gcBefore, long timestamp) { Comparator<Cell> comparator = filter.getColumnComparator(returnCF.getComparator()); Iterator<Cell> reduced = toCollate.size() == 1 ? toCollate.get(0) : MergeIterator.get(toCollate, comparator, getReducer(comparator)); filter.collectReducedColumns(returnCF, reduced, key, gcBefore, timestamp); }