code: def test_shapes_scalarvalue_derivative(self):
      P = KroghInterpolator(self.xs, self.ys)
      n = P.n
      assert_array_equal(np.shape(P.derivatives(0)), (n,))
      assert_array_equal(np.shape(P.derivatives(np.array(0))), (n,))
      assert_array_equal(np.shape(P.derivatives([0])), (n, 1))
      assert_array_equal(np.shape(P.derivatives([0, 1])), (n, 2))
  
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 12 for calling the TestKrogh obj's underlying member method code with example usage: obj.test_shapes_scalarvalue_derivative() without return types