def register_event(self):
""""""
self.event_engine.register(EVENT_TICK, self.process_tick_event)
self.event_engine.register(EVENT_CONTRACT, self.process_contract_event)
self.event_engine.register(EVENT_SPREAD_DATA, self.process_spread_event)
代码来源vnpy/app/data_recorder/engine.py
请教下EVENT_SPREAD_DATA这是什么数据引发的什么事件？
