code: def init_class_fixtures(cls):
      super(RollFinderTestCase, cls).init_class_fixtures()
  
      cls.volume_roll_finder = VolumeRollFinder(
          cls.trading_calendar,
          cls.asset_finder,
          cls.bcolz_future_daily_bar_reader,
      )
  
imports: from collections import deque
  from functools import partial
  from textwrap import dedent
  from numpy import arange, array, int64, full, repeat, tile
  from numpy.testing import assert_almost_equal
  import pandas
  from pandas import Timestamp, DataFrame
  from zipline.assets.continuous_futures import OrderedContracts, delivery_predicate
  from zipline.assets.roll_finder import ROLL_DAYS_FOR_CURRENT_CONTRACT, VolumeRollFinder
  from zipline.data.minute_bars import FUTURES_MINUTES_PER_DAY
  from zipline.errors import SymbolNotFound
  import zipline.testing.fixtures
label_desc: Use image node_id 1 for calling the RollFinderTestCase obj's underlying member method code with example usage: obj.init_class_fixtures(cls) without return types