HBASE-14208 moved TokenUtil from hbase-client to hbase-server.
I have a project depending on hbase-client 1.4.4, which I'd like to upgrade to 2.1.3. My project uses TokenUtil (specifically obtainAndCacheToken), which is included in hbase-client 1.4.4. At the same time I also have a dependency on Jetty 9.4, which is incompatible with the current version used by Hadoop. I can fix this for hbase-client by using hbase-shaded-client instead, since Jetty is shaded in this jar, but TokenUtil is only present in hbase-server as of 2.0.0. Since there is no hbase-shaded-server, I can't use TokenUtil and Jetty 9.4 at the same time.
TokenUtil can be split into server-only parts, and a client relevant part that can go back to hbase-client. The TokenUtil in hbase-server can retain the moved methods, and delegate to the util in hbase-client if backward compatibility is a concern.