Traceback (most recent call last):
File "C:\veighna_studio\lib\site-packages\vnpy\trader\ui\mainwindow.py", line 276, in open_widget
widget = widget_class(self.main_engine, self.event_engine)
File "C:\veighna_studio\lib\site-packages\vnpy_ctabacktester\ui\widget.py", line 56, in init
self.init_strategy_settings()
File "C:\veighna_studio\lib\site-packages\vnpy_ctabacktester\ui\widget.py", line 65, in init_strategy_settings
setting: dict = self.backtester_engine.get_default_setting(class_name)
File "C:\veighna_studio\lib\site-packages\vnpy_ctabacktester\engine.py", line 264, in get_default_setting
return strategy_class.get_class_parameters()
File "C:\veighna_studio\lib\site-packages\vnpy_ctastrategy\template.py", line 59, in get_class_parameters
class_parameters[name] = getattr(cls, name)
AttributeError: type object 'DemoStrategy' has no attribute 'fast_window'
