code: def test_None(self):
      a = dmatrix()
      l = sort(a, None)
      f = pytensor.function([a], l)
      gv = f(self.m_val)
      gt = np.sort(self.m_val, None)
      utt.assert_allclose(gv, gt)
  
imports: from functools import reduce
  from itertools import chain, product
  import numpy
  import pytest
  import pytensor
  from pytensor.compile.mode import Mode
  from pytensor.tensor.sort import ArgSortOp, SortOp, TopKOp, argsort, argtopk, sort, topk, topk_and_argtopk
  from pytensor.tensor.type import dmatrix, dvector, float_dtypes, integer_dtypes, lscalar, matrix, scalar, tensor, vector
  from tests import unittest_tools
label_desc: Use image node_id 7 for calling the TestSort obj's underlying member method code with example usage: obj.test_None() without return types