code: def testAnisotropicDiffusion_mixed_term_default_boundary(
      self, boundary_condition
  ):
      def pack_second_order_coeff_fn(u_yy, u_xy, u_xx):
          return [[u_yy, u_xy], [u_xy, u_xx]]
  
      self._testDiffusionInDiagonalDirection(
          pack_second_order_coeff_fn,
          boundary_condition=boundary_condition,
      )
  
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 8 for calling the MultidimParabolicEquationStepperTest obj's underlying member method code with example usage: obj.testAnisotropicDiffusion_mixed_term_default_boundary(boundary_condition) and returns: list