docstr: Tests that exceptions are properly raised.
docstr_tok: ["Tests","that","exceptions","are","properly","raised","."]
code: def test_less_that_two_nonzero_weights_exception_raised(self):
      """Tests that exceptions are properly raised."""
      self._generate_random_example()
      self.weights = tf.convert_to_tensor(
          value=np.array(
              [
                  [
                      [1.0, 1.0, 0.0, 0.0],
                      [1.0, 1.0, 0.0, 0.0],
                      [1.0, 1.0, 0.0, 0.0],
                  ],
                  [
                      [1.0, 1.0, 0.0, 0.0],
                      [1.0, 1.0, 0.0, 0.0],
                      [1.0, 0.0, 0.0, 0.0],
                  ],
              ],
              dtype=np.float64,
          )
      )
  
      with self.assertRaises(tf.errors.InvalidArgumentError):
          points = ray.triangulate(
              self.startpoints, self.endpoints, self.weights
          )
          self.evaluate(points)
  
imports: import sys
  from absl import flags
  from absl.testing import flagsaver
  from absl.testing import parameterized
  import numpy
  import tensorflow
  from tensorflow_graphics.geometry.representation import ray
  from tensorflow_graphics.util import test_case
label_desc: Use image node_id 14 for calling the RayTest obj's underlying member method code with example usage: obj.test_less_that_two_nonzero_weights_exception_raised() without return types