@Override
      public void flushcache() throws IOException {
        UTIL.getHBaseCluster().flushcache();
      }
Tests user specifiable time stamps putting, getting and scanning. Also tests same in presence
of deletes. Test cores are written so can be run against an HRegion and against an HTable: i.e.
both local and remote.
<p>
Port of old TestTimestamp test to here so can better utilize the spun up cluster running more
than a single test per spin up. Keep old tests' crazyness.
hbase-server/src/test/java/org/apache/hadoop/hbase/TestMultiVersions.java