List<K> batch = Lists.newArrayListWithCapacity(keyLimit);
for (Row<ByteBuffer, ByteBuffer> row : result.getResult()) {
if (!row.getColumns().isEmpty()) {
V lastValue = null;
for (Column<ByteBuffer> column : row.getColumns()) {
CompositeParser parser = Composites.newCompositeParser(column.getName());
lastValue = parser.read(valSerializer);
K key = parser.read(cfData.getKeySerializer());
if (indexCallback != null) {
if (!indexCallback.handleEntry(key, lastValue, column.getByteBufferValue())) {
continue;
}