throws IOException {
MultiIterator multiIterator = new MultiIterator(readers, false);
DeletingIterator delIter = new DeletingIterator(multiIterator, false);
ColumnFamilySkippingIterator cfsi = new ColumnFamilySkippingIterator(delIter);
ColumnQualifierFilter colFilter = new ColumnQualifierFilter(cfsi, columns);
VisibilityFilter visFilter = new VisibilityFilter(colFilter, Constants.NO_AUTHS, new byte[0]);
visFilter.seek(r, LocalityGroupUtil.EMPTY_CF_SET, false);
VersioningIterator vi = new VersioningIterator();
Map<String,String> opts = new HashMap<String,String>();
opts.put("maxVersions", "1");
vi.init(visFilter, opts, null);