protected Collection<FileInfo> loadFileInfos() {
   Cursor cursor = myDatabase.rawQuery("SELECT file_id,name,parent_id,size FROM Files", null);
   HashMap<Long, FileInfo> infosById = new HashMap<Long, FileInfo>();
   while (cursor.moveToNext()) {
     final long id = cursor.getLong(0);
     final FileInfo info =
         createFileInfo(
             id, cursor.getString(1), cursor.isNull(2) ? null : infosById.get(cursor.getLong(2)));
     if (!cursor.isNull(3)) {
       info.FileSize = cursor.getLong(3);
     }
     infosById.put(id, info);
   }
   cursor.close();
   return infosById.values();
 }