在 这个 C:\veighna_studio\Lib\site-packages\vnpy_ctastrategy\engine.py 文件里，有如下代码
class CtaEngine(BaseEngine):
""""""
engine_type: EngineType = EngineType.LIVE # live trading engine
setting_filename: str = "cta_strategy_setting.json"
data_filename: str = "cta_strategy_data.json"
def __init__(self, main_engine: MainEngine, event_engine: EventEngine) -> None:
""""""
super().__init__(main_engine, event_engine, APP_NAME)
self.strategy_setting: dict = {} # strategy_name: dict
self.strategy_data: dict = {} # strategy_name: dict
请问：
self.strategy_setting: dict = {} 键是什么？值是什么？能简单举个例子吗
self.strategy_data: dict = {} 键是什么？值是什么？能简单举个例子吗
