class_docstr: A class for order creation following an order being complete.
  
  Parameters
  ----------
  side : `TradeSide`
      The trading side of the specification.
  trade_type : `TradeType`
      The type of trade for the specification.
  exchange_pair : `ExchangePair`
      The exchange pair for the specification.
  criteria : `Callable[[Order, Exchange], bool]`
      The criteria for executing the order after its been created.
code: def __str__(self) -> str:
      data = ["{}={}".format(k, v) for k, v in self.to_dict().items()]
      return "<{}: {}>".format(self.__class__.__name__, ", ".join(data))
  
file_path: tensortrade/tensortrade/oms/orders/order_spec.py
imports: from typing import Callable
  from tensortrade.core import Identifiable
  from tensortrade.oms.orders import Order, TradeSide, TradeType
label_desc: Use image node_id 4 for calling the OrderSpec obj's underlying member method code with example usage: obj.__str__() and returns: str