add type check when it is class foundation

[MapleYin]

如果一个类的定义为：

@interface MJPerson : NSObject
@property (copy, nonatomic) NSString *name;
@property (nonatomic) BOOL isVIP;
@property (strong, nonatomic) NSArray<MJPerson *> *friends;
@property (strong, nonatomic) NSArray<NSString *> *books;
@end

但是给的 json 数据形如：

{
    "name": "myName",
    "isVIP": false,
    "friends": [],
    "books": ["book1", "book2", null, false, 123]
}

此时获得的模型中，books 属性就不能保证是 NSString 了