= market @abc.abstractmethod def buy_order(self, price: float, budget: float) -> Order: raise NotImplementedError @abc.abstractmethod def sell_order(self, price: float, volume: float) -> Order: raise NotImplementedError @abc.abstractmethod def cancel_order(self, order_id: str) -> str: raise NotImplementedError @abc.abstractmethod def get_order(self, order_id: str) -> Order: raise NotImplementedError @abc.abstractmethod def get_orders(self, order_ids: List[str]=None) -> List[Order]: raise NotImplementedError @abc.abstractmethod def get_prices(self, unit: str='minute', counts: int=1, to: datetime=None) -> List[Price]: raise NotImplementedError @abc.abstractmethod def get_balance(self) -> Balance: raise NotImplementedError