code: def test_monotone(self, xp, scp):
      # PCHIP should preserve monotonicty
      p, xi, _ = self._make_random(xp, scp)
      results = []
      for i in range(len(xi) - 1):
          x1, x2 = xi[i], xi[i + 1]
          x = xp.linspace(x1, x2, 10)
          yp = p(x)
          results.append(yp)
      return results
  
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 3 for calling the TestPCHIP obj's underlying member method code with example usage: obj.test_monotone(xp, scp) and returns: results