如果我在买入卖出时都以市价单来进行交易，可以通过修改OrderData来实现吗？
`@dataclass
class OrderData(BaseData):
"""
Order data contains information for tracking lastest status
of a specific order.
"""
symbol: str
exchange: Exchange
orderid: str
type: OrderType = OrderType.MARKET
direction: Direction = None
offset: Offset = Offset.NONE
price: float = 0
volume: float = 0
traded: float = 0
status: Status = Status.SUBMITTING
datetime: datetime = None
reference: str = ""`
比如我这里直接将OrderType改为了MARKET，那么在原来的下单函数处要修改吗？
比如self.buy(bar.close_price,1)该怎么修改呢？
