throws IOException {
MultiIterator multiIterator = new MultiIterator(readers, false);
DeletingIterator delIter = new DeletingIterator(multiIterator, false);
SystemScanIterator ssi = new SystemScanIterator(delIter, Constants.NO_AUTHS, new byte[0], columns);
ssi.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(ssi, opts, null);