@Override
    public String toString() {
      if (this.bytes == null || this.bytes.length == 0) {
        return "empty";
      }
      return keyToString(this.bytes, this.offset, getKeyLength()) + "/vlen=0/mvcc=0";
    }
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