class_docstr: Model slippage as a fixed value.
  
  Parameters
  ----------
  slippage : float, optional
      fixed slippage will be added to buys and subtracted from sells.
class_docstr_tok: ["Model","slippage","as","a","fixed","value",".","Parameters","--","--","--","--","--","slippage",":","float",",","optional","fixed","slippage","will","be","added","to","buys","and","subtracted","from","sells","."]
code: def process_order(self, data, order):
      price = data.current(order.asset, "close")
  
      if order.amount > 0:
          # Buy order
          adj_price = price * (1 + self.slippage)
      else:
          # Sell order
          adj_price = price * (1 - self.slippage)
  
      log.debug(
          "added slippage to price: {} => {}".format(price, adj_price)
      )
  
      return adj_price, order.amount
  
imports: import numpy
  import pandas
  from logbook import Logger
  from redo import retry
  from catalyst.assets._assets import TradingPair
  from catalyst.constants import LOG_LEVEL
  from catalyst.exchange.exchange_errors import ExchangeRequestError
  from catalyst.finance.blotter import Blotter
  from catalyst.finance.commission import CommissionModel
  from catalyst.finance.order import ORDER_STATUS
  from catalyst.finance.slippage import SlippageModel
  from catalyst.finance.transaction import create_transaction
  from catalyst.utils.input_validation import expect_types
label_desc: Use image node_id 4 for calling the TradingPairFixedSlippage obj's underlying member method code with example usage: obj.process_order(data, order) and returns: adj_price,  order