@Override
    protected RSRpcServices createRpcServices() throws IOException {
      return new DelayedRSRpcServices(this);
    }
Tests that scan on a table throws {@link RetriesExhaustedException} when the operation takes
longer than 'hbase.client.scanner.timeout.period'.
hbase-server/src/test/java/org/apache/hadoop/hbase/TestClientOperationTimeout.java