@Override
      public void call() throws Exception {
        Get get1 = new Get(ROW);
        get1.addColumn(FAMILY, QUALIFIER);
        Get get2 = new Get(ROW);
        get2.addColumn(FAMILY, QUALIFIER);
        List<Get> gets = new ArrayList<>();
        gets.add(get1);
        gets.add(get2);
        TABLE.batch(gets, 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