docstr: adds the last order into .orders
  :return:
docstr_tok: ["adds","the","last","order","into",".orders",":","return",":"]
code: def mod_last_order(self):
      """
      adds the last order into .orders
      :return:
      """
      self.last_order = True
      asset = [
          pair
          for pair in self.exchange.assets
          if pair.symbol == "eth_usdt"
      ][0]
      orders_dict = self.create_orders_dict(asset, self.last_order)
      self.exchange.api.orders = orders_dict
  
imports: from logbook import Logger
  from mock import patch, create_autospec, MagicMock, Mock
  import pandas
  from ccxt.base.errors import RequestTimeout
  from catalyst.exchange.exchange_errors import ExchangeRequestError
  from .base import BaseExchangeTestCase
  from catalyst.exchange.ccxt.ccxt_exchange import CCXT
  from catalyst.exchange.exchange_execution import ExchangeLimitOrder
  from catalyst.exchange.utils.exchange_utils import get_exchange_auth
  from catalyst.finance.order import Order
label_desc: Use image node_id 4 for calling the TestCCXT obj's underlying member method code with example usage: obj.mod_last_order() without return types