code: def _calculate_impact(self, test_order, answer_key):
      model = VolatilityVolumeShare(volume_limit=0.05)
      first_minute = pd.Timestamp("2006-03-31 11:35AM", tz="UTC")
  
      next_3_minutes = self.trading_calendar.minutes_window(
          first_minute, 3
      )
      remaining_shares = test_order.open_amount
  
      for i, minute in enumerate(next_3_minutes):
          data = self.create_bardata(simulation_dt_func=lambda: minute)
          new_order = Order(
              dt=data.current_dt,
              asset=self.ASSET,
              amount=remaining_shares,
          )
          price, amount = model.process_order(data, new_order)
  
          self.assertEqual(price, answer_key[i][0])
          self.assertEqual(amount, answer_key[i][1])
  
          amount = amount or 0
          if remaining_shares < 0:
              remaining_shares = min(0, remaining_shares - amount)
          else:
              remaining_shares = max(0, remaining_shares - amount)
  
imports: from collections import namedtuple
  import datetime
  from math import sqrt
  from nose_parameterized import parameterized
  from pandas.tslib import normalize_date
  import numpy
  import pandas
  import pytz
  from catalyst.assets import Equity, Future
  from catalyst.data.data_portal import DataPortal
  from catalyst.finance.asset_restrictions import NoRestrictions
  from catalyst.finance.order import Order
  from catalyst.finance.slippage import EquitySlippageModel, fill_price_worse_than_limit_price, FutureSlippageModel, SlippageModel, VolatilityVolumeShare, VolumeShareSlippage
  from catalyst.protocol import DATASOURCE_TYPE, BarData
  from catalyst.testing import create_minute_bar_data, tmp_bcolz_equity_minute_bar_reader
  from catalyst.testing.fixtures import WithCreateBarData, WithDataPortal, WithSimParams, WithTradingEnvironment, CatalystTestCase
  from catalyst.utils.classproperty import classproperty
label_desc: Use image node_id 6 for calling the VolatilityVolumeShareTestCase obj's underlying member method code with example usage: obj._calculate_impact(test_order, answer_key) without return types