code: def test_neg_axis(self, xp, scp):
      k = 2
      t = xp.asarray([0, 1, 2, 3, 4, 5, 6])
      c = xp.asarray([[-1, 2, 0, -1], [2, 0, -3, 1]])
  
      spl = scp.interpolate.BSpline(t, c, k, axis=-1)
      return spl(xp.asarray([2.5]))
  
imports: import pytest
  import inspect
  from cupy import testing
  from cupy_backends.cuda.api import driver
  from cupy_backends.cuda.api import runtime
  import numpy
  import cupyx.scipy.interpolate
label_desc: Use image node_id 28 for calling the TestBSpline obj's underlying member method code with example usage: obj.test_neg_axis(xp, scp) and returns: spl