code: def test_brdf_jacobian_preset(self):
      direction_incoming_light_init = np.array((0.0, 1.0, 0.0))
      direction_outgoing_light_init = np.array((0.0, 1.0, 0.0))
      surface_normal_init = np.array((1.0, 0.0, 0.0))
      albedo_init = np.array((1.0, 1.0, 1.0))
  
      def lamertian_brdf_fn(albedo):
          return lambertian.brdf(
              direction_incoming_light_init,
              direction_outgoing_light_init,
              surface_normal_init,
              albedo,
          )
  
      self.assert_jacobian_is_correct_fn(
          lamertian_brdf_fn, [albedo_init]
      )
  
file_path: graphics/tensorflow_graphics/rendering/reflectance/tests/lambertian_test.py
imports: import math
  import sys
  from absl.testing import flagsaver
  from absl.testing import parameterized
  import numpy
  import tensorflow
  from tensorflow_graphics.rendering.reflectance import lambertian
  from tensorflow_graphics.util import test_case
label_desc: Use image node_id 2 for calling the LambertianTest obj's underlying member method code with example usage: obj.test_brdf_jacobian_preset() and returns: lambertian