public static ExecutorService getPoolThreadExecutor() {
        setup();
        return poolThreadExecutor;
    }
@Test
    public void poolThread() {
        ExecutorService a =  SharedExecutors.getPoolThreadExecutor();
        assertNotNull("ExecutorService must not be null", a);
        ExecutorService b =  SharedExecutors.getPoolThreadExecutor();
        assertSame("factories should be same", a, b);

    }