code: def test_derivatives_complex(self, xp, scp):
      x = xp.array([-1, -1, 0, 1, 1])
      y = xp.array([1, 1.0j, 0, -1, 1.0j])
      P = scp.interpolate.KroghInterpolator(x, y)
      D = P.derivatives(xp.array(0))
      return D
  
imports: import io
  import warnings
  import numpy
  import pytest
  import cupy
  from cupy.cuda import runtime
  from cupy import testing
  import cupyx.scipy.interpolate
  from cupyx.scipy.interpolate import CubicHermiteSpline
label_desc: Use image node_id 18 for calling the TestKrogh obj's underlying member method code with example usage: obj.test_derivatives_complex(xp, scp) and returns: D