code: def test_low_derivatives(self):
      P = KroghInterpolator(self.xs, self.ys)
      D = P.derivatives(self.test_xs, len(self.xs) + 2)
      for i in xrange(D.shape[0]):
          assert_almost_equal(
              self.true_poly.deriv(i)(self.test_xs), D[i]
          )
  
imports: from __future__ import division, print_function, absolute_import
  import warnings
  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, pchip, PchipInterpolator, pchip_interpolate, Akima1DInterpolator, CubicSpline, make_interp_spline
  from scipy._lib.six import xrange
label_desc: Use image node_id 5 for calling the TestKrogh obj's underlying member method code with example usage: obj.test_low_derivatives() without return types