code: def unsubscribe(id_or_symbols):
      
      current_universe = Environment.get_instance().get_universe()
      if isinstance(id_or_symbols, six.string_types):
          order_book_id = instruments(id_or_symbols).order_book_id
          current_universe.discard(order_book_id)
      elif isinstance(id_or_symbols, Instrument):
          current_universe.discard(id_or_symbols.order_book_id)
      elif isinstance(id_or_symbols, Iterable):
          for item in id_or_symbols:
              i = assure_order_book_id(item)
              current_universe.discard(i)
      else:
          raise RQInvalidArgument(_(u"unsupported order_book_id type"))
  
      Environment.get_instance().update_universe(current_universe)
docs: 取消订阅合约行情。取消订阅会导致合约池内合约的减少，如果当前合约池中没有任何合约，则策略直接退出。
  
      :param id_or_symbols: 标的物
      :type id_or_symbols: :class:`~Instrument` object | `str` | List[:class:`~Instrument`] | List[`str`]