@Override
    public ByteBuffer getTagsByteBuffer() {
      return this.tags == null ? HConstants.EMPTY_BYTE_BUFFER : ByteBuffer.wrap(this.tags);
    }
@param cell The original ByteBufferExtendedCell which it rewrites
@param tags the tags bytes. The array suppose to contain the tags bytes alone.
hbase-common/src/main/java/org/apache/hadoop/hbase/PrivateCellUtil.java