添加单元测试，测试 PojoUtils 是否能正确处理 list -> pojo -> list -> pojo 这种类型的对象

dubbo-common/src/test/java/com/alibaba/dubbo/common/utils/PojoUtilsTest.java

@@ -636,6 +636,45 @@ public void testPojoList() throws Exception {
         Assert.assertEquals(parent.getAge(), realizeParent.getAge());
     }
 
+    @Test
+    public void testListPojoListPojo() throws Exception {
+        InnerPojo<Parent> parentList = new InnerPojo<Parent>();
+        Parent parent = new Parent();
+        parent.setName("zhangsan");
+        parent.setAge(Integer.MAX_VALUE);
+        parentList.setList(Arrays.asList(parent));
+
+        ListResult<InnerPojo<Parent>> list = new ListResult<InnerPojo<Parent>>();
+        list.setResult(Arrays.asList(parentList));
+
+        Object generializeObject = PojoUtils.generalize(list);
+        Object realizeObject = PojoUtils.realize(generializeObject, ListResult.class);
+
+        Assert.assertTrue(realizeObject instanceof ListResult);
+        ListResult realizeList = (ListResult)realizeObject;
+        List realizeInnerList = realizeList.getResult();
+        Assert.assertEquals(1, realizeInnerList.size());
+        Assert.assertTrue(realizeInnerList.get(0) instanceof InnerPojo);
+        InnerPojo realizeParentList = (InnerPojo)realizeInnerList.get(0);
+        Assert.assertEquals(1, realizeParentList.getList().size());
+        Assert.assertTrue(realizeParentList.getList().get(0) instanceof Parent);
+        Parent realizeParent = (Parent)realizeParentList.getList().get(0);
+        Assert.assertEquals(parent.getName(), realizeParent.getName());
+        Assert.assertEquals(parent.getAge(), realizeParent.getAge());
+    }
+
+    public static class InnerPojo<T> {
+        private List<T> list;
+
+        public List<T> getList() {
+            return list;
+        }
+
+        public void setList(List<T> list) {
+            this.list = list;
+        }
+    }
+
     public static class ListResult<T> {
         List<T> result;