@Override
    protected void decodeFirst() {
      currentBuffer.skip(Bytes.SIZEOF_INT);
      current.lastCommonPrefix = 0;
      decodeNext();
    }
Just copy data, do not do any kind of compression. Use for comparison and benchmarking.
hbase-common/src/main/java/org/apache/hadoop/hbase/io/encoding/CopyKeyDataBlockEncoder.java