@Override
  public ExtendedCell deepClone() {
    byte[] copy = Bytes.copy(this.bytes, this.offset, this.length);
    KeyValue kv = new NoTagsKeyValue(copy, 0, copy.length);
    kv.setSequenceId(this.getSequenceId());
    return kv;
  }
An extension of the KeyValue where the tags length is always 0
hbase-common/src/main/java/org/apache/hadoop/hbase/NoTagsKeyValue.java