code: def test_scalar(self, xp, scp, dtype):
      if xp.dtype(dtype).kind in "u":
          pytest.skip()
      true_poly = numpy.poly1d([-1, 2, 6, -3, 2])
      xs = numpy.linspace(-1, 1, 10, dtype=dtype)
      ys = true_poly(xs)
      if xp is cupy:
          xs = cupy.asarray(xs)
          ys = cupy.asarray(ys)
      P = scp.interpolate.KroghInterpolator(xs, ys)
      return P(xp.array(7, dtype=dtype))
  
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 2 for calling the TestKrogh obj's underlying member method code with example usage: obj.test_scalar(xp, scp, dtype) and returns: P