code: @Override public void syncCacheToDB(List<Integer> idList) throws IOException {
          final SQLiteDatabase database = sqLiteHelper.getWritableDatabase();
          database.beginTransaction();
          try {
              for (Integer id : idList) {
                  syncCacheToDB(id);
              }
              database.setTransactionSuccessful();
          } finally {
              database.endTransaction();
          }
      }
docs: following accept database operation what is controlled by helper.