code: def test_recode_series(self):
      series = Series(
          ["a", "b"] * 10, index=np.arange(0, 40, 2), name="index_test"
      )
      series_ = _recode(series, {"a": 0, "b": 1})
      assert_equal(
          series_.index.values,
          series.index.values,
          err_msg="_recode changed the index",
      )
  
file_path: statsmodels/statsmodels/graphics/tests/test_factorplots.py
imports: import numpy
  from numpy.testing import assert_equal, assert_raises
  from pandas import Series
  import pytest
  from statsmodels.graphics.factorplots import _recode, interaction_plot
label_desc: Use image node_id 8 for calling the TestInteractionPlot obj's underlying member method code with example usage: obj.test_recode_series() without return types