code: def test_grad_negative_axis_2d(self):
      data = np.random.rand(2, 3).astype(theano.config.floatX)
      utt.verify_grad(lambda x: sort(x, -1), [data])
      data = np.random.rand(2, 3).astype(theano.config.floatX)
      utt.verify_grad(lambda x: sort(x, -2), [data])
  
imports: from __future__ import absolute_import, print_function, division
  from itertools import product, chain
  from functools import reduce
  import unittest
  from theano.tests import unittest_tools
  import numpy
  import theano
  from theano import tensor
  from theano.tensor.sort import sort, SortOp
  from theano.tensor.sort import argsort, ArgSortOp
  from theano.tensor.sort import topk, argtopk, topk_and_argtopk, TopKOp
label_desc: Use image node_id 10 for calling the Test_sort obj's underlying member method code with example usage: obj.test_grad_negative_axis_2d() without return types