@Override
    public ExtendedCell getCell() {
      return current.toCell();
    }
Copies only the key part of the keybuffer by doing a deep copy and passes the seeker state
members for taking a clone. Note that the value byte[] part is still pointing to the
currentBuffer and represented by the valueOffset and valueLength
hbase-common/src/main/java/org/apache/hadoop/hbase/io/encoding/BufferedDataBlockEncoder.java