@Test
	public void testMap() {
		ExecutorService threadPool = Executors.newSingleThreadExecutor();
		
		
		Map<String, Integer> _map = new HashMap<>();
		_map.put("1", 1);
		_map.put("22", 22);
		map = _map;
		
		threadPool.execute(new Runnable() {
			@Override
			public void run() {
				for (Map.Entry<String, Integer> entry : map.entrySet()) {
					System.out.printf(entry + " ");
					try {
						Thread.sleep(1000);
					} catch (InterruptedException e) {
						e.printStackTrace();
					}
				}
				System.out.println();
			}
		});
		
		_map = new HashMap<>();
		_map.put("a", 1323);
		try {
			Thread.sleep(100);
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
		_map.put("bb", 33);
		map = _map;
		System.err.println(map);
		
		threadPool.shutdown();
		try {
			Thread.sleep(3000);
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
	}