code: def test_quantile_turnover(
      self, quantile_values, freq, test_quantile, period, expected_vals
  ):
      dr = date_range(
          start="2015-1-1", periods=len(quantile_values), freq=freq
      )
      dr.name = "date"
      tickers = ["A", "B", "C", "D"]
  
      quantized_test_factor = Series(
          DataFrame(
              index=dr, columns=tickers, data=quantile_values
          ).stack()
      )
      quantized_test_factor.index = (
          quantized_test_factor.index.set_names(["date", "asset"])
      )
  
      to = quantile_turnover(
          quantized_test_factor, test_quantile, period
      )
  
      expected = Series(
          index=quantized_test_factor.index.levels[0],
          data=expected_vals,
      )
      expected.name = test_quantile
  
      assert_series_equal(to, expected)
  
imports: from __future__ import division
  from unittest import TestCase
  from parameterized import parameterized
  from numpy import nan
  from pandas import Series, DataFrame, date_range, MultiIndex, Int64Index, Index, DatetimeIndex, Timedelta
  from pandas.tseries.offsets import BDay, Day, CDay
  from pandas.util.testing import assert_frame_equal, assert_series_equal
  from ..performance import factor_information_coefficient, mean_information_coefficient, mean_return_by_quantile, quantile_turnover, factor_rank_autocorrelation, factor_returns, factor_alpha_beta, cumulative_returns, factor_weights, common_start_returns, average_cumulative_return_by_quantile
  from ..utils import get_forward_returns_columns, get_clean_factor_and_forward_returns
label_desc: Use image node_id 4 for calling the PerformanceTestCase obj's underlying member method code with example usage: obj.test_quantile_turnover(quantile_values, freq, test_quantile, period, expected_vals) without return types