code: def test_second_derivative_continuity_gh_11758(self):
      # gh-11758: C2 continuity fail
      x = np.array(
          [
              0.9,
              1.3,
              1.9,
              2.1,
              2.6,
              3.0,
              3.9,
              4.4,
              4.7,
              5.0,
              6.0,
              7.0,
              8.0,
              9.2,
              10.5,
              11.3,
              11.6,
              12.0,
              12.6,
              13.0,
              13.3,
          ]
      )
      y = np.array(
          [
              1.3,
              1.5,
              1.85,
              2.1,
              2.6,
              2.7,
              2.4,
              2.15,
              2.05,
              2.1,
              2.25,
              2.3,
              2.25,
              1.95,
              1.4,
              0.9,
              0.7,
              0.6,
              0.5,
              0.4,
              1.3,
          ]
      )
      S = CubicSpline(x, y, bc_type="periodic", extrapolate="periodic")
      self.check_correctness(S, "periodic", "periodic")
  
imports: import warnings
  import io
  import numpy
  from numpy.testing import assert_almost_equal, assert_array_equal, assert_array_almost_equal, assert_allclose, assert_equal, assert_
  from pytest import raises
  from scipy.interpolate import KroghInterpolator, krogh_interpolate, BarycentricInterpolator, barycentric_interpolate, approximate_taylor_polynomial, CubicHermiteSpline, pchip, PchipInterpolator, pchip_interpolate, Akima1DInterpolator, CubicSpline, make_interp_spline
label_desc: Use image node_id 6 for calling the TestCubicSpline obj's underlying member method code with example usage: obj.test_second_derivative_continuity_gh_11758() without return types