code: def testAnisotropicDiffusion_TwoDimList_WithoutRedundantElement(self):
      def pack_second_order_coeff_fn(u_yy, u_xy, u_xx):
          return [[u_yy, u_xy], [None, u_xx]]
  
      self._testDiffusionInDiagonalDirection(pack_second_order_coeff_fn)
  
imports: from absl.testing import parameterized
  import numpy
  import tensorflow.compat.v2
  import tf_quant_finance
  from tensorflow.python.framework import test_util
label_desc: Use image node_id 5 for calling the MultidimParabolicEquationStepperTest obj's underlying member method code with example usage: obj.testAnisotropicDiffusion_TwoDimList_WithoutRedundantElement() and returns: list