code: def _make_random(self, npts=20):
      np.random.seed(1234)
      xi = np.sort(np.random.random(npts))
      yi = np.random.random(npts)
      return pchip(xi, yi), xi, yi
  
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 1 for calling the TestPCHIP obj's underlying member method code with example usage: obj._make_random(npts) and returns: pchip,  xi,  yi