code: def test_no_roll(self):
      # If we call 'get_rolls' with start and end dates that do not have any
      # rolls between them, we should still expect the last roll date to be
      # computed successfully.
      date_not_near_roll = pd.Timestamp("2017-02-01", tz="UTC")
      rolls = self.volume_roll_finder.get_rolls(
          root_symbol="CL",
          start=date_not_near_roll,
          end=date_not_near_roll + self.trading_calendar.day,
          offset=0,
      )
      self.assertEqual(rolls, [(1001, None)])
  
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 5 for calling the RollFinderTestCase obj's underlying member method code with example usage: obj.test_no_roll() without return types