如何在Parse（Java）中通过Pointer值查询Class？

Question

我在这里得到一个NullPointer，显然是因为我的查询格式不正确。我的印象是，我可以通过提供匹配它的对象来查询我的类中的Pointer列。为什么当前用户不够？

    ParseUser currentUser = ParseUser.getCurrentUser();

    ParseQuery<ParseObject> requestsQuery = ParseQuery.getQuery("Request");
        requestsQuery.whereEqualTo("author", currentUser);
        requestsQuery.findInBackground(new FindCallback<ParseObject>() {
            @Override
            public void done(List<ParseObject> requestList, ParseException e) {
                if (e == null) {
                    log.info(requestList.toString());

                }

            }
     });

空指针：

[WARNING] 
java.lang.NullPointerException
    at com.nnit.automation.controller.IndexController$1.done(IndexController.java:58)
    at org.parse4j.ParseQuery$FindInBackgroundThread.run(ParseQuery.java:623)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)