如何在App Engine文件API中找到未终结的文件？

The App Engine files API allows a file to be created either in blobstore or in cloud storage. A file basically has two states: a unfinalized state where you can still append to the file and a finalized state where the file cannot be appended but where you can read from the file or serve it through blobstore or cloud storage.The App Engine files API allows a file to be cr