class_docstr: Base strategy for trading
class_docstr_tok: ["Base","strategy","for","trading"]
docstr: get trade exchange in a prioritized order
docstr_tok: ["get","trade","exchange","in","a","prioritized","order"]
code: def trade_exchange(self) -> Exchange:
      """get trade exchange in a prioritized order"""
      return getattr(
          self, "_trade_exchange", None
      ) or self.common_infra.get("trade_exchange")
  
imports: from __future__ import annotations
  from abc import ABCMeta, abstractmethod
  from typing import Any, Generator, Optional, TYPE_CHECKING, Union
  from typing import Tuple
  from ..backtest.decision import BaseTradeDecision
  from ..backtest.utils import CommonInfrastructure, LevelInfrastructure, TradeCalendarManager
  from ..rl.interpreter import ActionInterpreter, StateInterpreter
  from ..utils import init_instance_by_config
label_desc: Use image node_id 5 for calling the BaseStrategy obj's underlying member method code with example usage: obj.trade_exchange() and returns: unknown