@Test
    public void testPut() {
        SafeConcurrentHashMap<Object, Object> map = new SafeConcurrentHashMap<>();
        Assert.assertNull(map.put(null, null));
        Assert.assertNull(map.put(null, "value"));
        Assert.assertNull(map.put("key", null));
        Assert.assertEquals(0, map.size());
        Assert.assertNull(map.put("key", "value"));
        Assert.assertEquals(1, map.size());
    }
@author <a href=mailto:orezsilence@163.com>zhangchengxi</a>
core/api/src/test/java/com/alipay/sofa/rpc/core/util/SafeConcurrentHashMapTest.java