code: def test_interpolate_cubicspline(self):
      pytest.importorskip("scipy")
      ser = Series([10, 11, 12, 13])
  
      expected = Series(
          [
              11.00,
              11.25,
              11.50,
              11.75,
              12.00,
              12.25,
              12.50,
              12.75,
              13.00,
          ],
          index=Index(
              [1.0, 1.25, 1.5, 1.75, 2.0, 2.25, 2.5, 2.75, 3.0]
          ),
      )
      # interpolate at new_index
      new_index = ser.index.union(
          Index([1.25, 1.5, 1.75, 2.25, 2.5, 2.75])
      ).astype(float)
      result = (
          ser.reindex(new_index)
          .interpolate(method="cubicspline")
          .loc[1:3]
      )
      tm.assert_series_equal(result, expected)
  
imports: import numpy
  import pytest
  import pandas.util._test_decorators
  import pandas
  from pandas import Index, MultiIndex, Series, date_range, isna
  import pandas._testing
label_desc: Use image node_id 4 for calling the TestSeriesInterpolateData obj's underlying member method code with example usage: obj.test_interpolate_cubicspline() without return types