code: def setUp(self):
      BaseTestCase.setUp(self)
      self.priceImpact = 0.1
      self.slippage = slippage.VolumeShareSlippage(self.priceImpact)
      self.barsBuilder = broker_backtesting_test.BarsBuilder(
          BaseTestCase.TestInstrument, bar.Frequency.DAY
      )
  
imports: import unittest
  from .None import broker_backtesting_test
  from pyalgotrade import broker
  from pyalgotrade.broker import slippage
  from pyalgotrade.broker import backtesting
  from pyalgotrade import bar
label_desc: Use image node_id 1 for calling the VolumeShareSlippageTestCase obj's underlying member method code with example usage: obj.setUp() without return types