code: def test_cspline_zero(self, xp, scp):
      return scp.signal.cspline1d(xp.asarray([0]))
  
imports: import sys
  import unittest
  import pytest
  import cupy
  from cupy import testing
  import cupyx.scipy.signal
  import numpy
label_desc: Use image node_id 1 for calling the TestCSpline obj's underlying member method code with example usage: obj.test_cspline_zero(xp, scp) and returns: scp