docstr: Tests that generate_l_m_zonal produces the expected results.
docstr_tok: ["Tests","that","generate_l_m_zonal","produces","the","expected","results","."]
code: def test_generate_l_m_zonal_preset(self):
      """Tests that generate_l_m_zonal produces the expected results."""
      l, m = spherical_harmonics.generate_l_m_zonal(2)
  
      self.assertAllEqual(l, (0, 1, 2))
      self.assertAllEqual(m, (0, 0, 0))
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import sys
  from absl.testing import parameterized
  import numpy
  import tensorflow
  from tensorflow_graphics.math import math_helpers
  from tensorflow_graphics.math import spherical_harmonics
  from tensorflow_graphics.util import asserts
  from tensorflow_graphics.util import test_case
label_desc: Use image node_id 10 for calling the SphericalHarmonicsTest obj's underlying member method code with example usage: obj.test_generate_l_m_zonal_preset() without return types