docstr: Tests the triangle normal assertion.
docstr_tok: ["Tests","the","triangle","normal","assertion","."]
code: def test_normal_assert(self, v0, v1, v2):
      """Tests the triangle normal assertion."""
      with self.assertRaises(tf.errors.InvalidArgumentError):
          self.evaluate(triangle.normal(v0, v1, v2))
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from absl.testing import parameterized
  import numpy
  from six.moves import range
  import tensorflow
  from tensorflow_graphics.geometry.representation import triangle
  from tensorflow_graphics.math import vector
  from tensorflow_graphics.util import test_case
label_desc: Use image node_id 1 for calling the TriangleTest obj's underlying member method code with example usage: obj.test_normal_assert(v0, v1, v2) without return types