@classmethod
def restore_from_snapshot_and_diffs(self, snapshot: OrderBookMessage, diffs: List[OrderBookMessage]):
    raise NotImplementedError((constants.EXCHANGE_NAME + ' order book needs to retain individual order data.'))
@classmethod
def restore_from_snapshot_and_diffs(self, snapshot: OrderBookMessage, diffs: List[OrderBookMessage]):
    raise NotImplementedError((constants.EXCHANGE_NAME + ' order book needs to retain individual order data.'))