code: def test_complex():
      x = [1, 2, 3, 4]
      y = [1, 2, 1j, 3]
  
      for ip in [
          KroghInterpolator,
          BarycentricInterpolator,
          pchip,
          CubicSpline,
      ]:
          p = ip(x, y)
          assert_allclose(y, p(x))
  
      dydx = [0, -1j, 2, 3j]
      p = CubicHermiteSpline(x, y, dydx)
      assert_allclose(y, p(x))
      assert_allclose(dydx, p(x, 1))
  
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 5 for calling a global function with example usage: test_complex() without return types