Traceback (most recent call last):
File "D:/pycharm/huice2/yuncodes/backtest/class_04_prepare_data.py", line 96, in <module>
main()
File "D:/pycharm/huice2/yuncodes/backtest/class_04_prepare_data.py", line 81, in main
main_engine.add_app(CsvLoaderApp)
NameError: name 'CsvLoaderApp' is not defined
