@Override
      public void call() throws Exception {
        Put put1 = new Put(ROW);
        put1.addColumn(FAMILY, QUALIFIER, VALUE);
        Put put2 = new Put(ROW);
        put2.addColumn(FAMILY, QUALIFIER, VALUE);
        List<Put> puts = new ArrayList<>();
        puts.add(put1);
        puts.add(put2);
        TABLE.batch(puts, new Object[2]);
      }
Tests that one can implement their own RpcControllerFactory and expect it to successfully pass
custom priority values to the server for all HTable calls.
hbase-server/src/test/java/org/apache/hadoop/hbase/TestCustomPriorityRpcControllerFactory.java