Android SDK 遍历AVQuery onNext回调返回的List数据报错

public class MappingTable extends AVObject {}

AVQuery<MappingTable> avQuery = new AVQuery<>("MappingTable");
avQuery.findInBackground().subscribe(new Observer<List<MappingTable>>() {
    @Override
    public void onSubscribe(@NonNull Disposable d) {

    }

    @Override
    public void onNext(@NonNull List<MappingTable> mappingTables) {
        for (MappingTable mappingTable : mappingTables){

        }
    }

    @Override
    public void onError(@NonNull Throwable e) {

    }

    @Override
    public void onComplete() {

    }
});

如图,onNext返回的mappingTables是没有办法遍历的,直接报错
java.lang.ClassCastException: cn.leancloud.AVObject cannot be cast to cn.xxx.MappingTable

这个地方到底应该怎么用呢?

打断点的确还是AVObject对象

没有人嘛?