@Override
  public ExtendedCell deepClone() {
    byte[] copy = Bytes.copy(this.bytes, this.offset, this.length);
    KeyValue kv = new KeyValue(copy, 0, copy.length);
    kv.setSequenceId(this.getSequenceId());
    return kv;
  }
A setter that helps to avoid object creation every time and whenever there is a need to
create new KeyOnlyKeyValue.
@param key    Key to set
@param offset Offset of the Key
@param length length of the Key
hbase-common/src/main/java/org/apache/hadoop/hbase/KeyValue.java