docstr: Tests that exceptions are properly raised.
docstr_tok: ["Tests","that","exceptions","are","properly","raised","."]
code: def test_negative_weights_exception_raised(self):
      """Tests that exceptions are properly raised."""
      self._generate_random_example()
      self.weights = -1.0 * tf.ones_like(self.weights, dtype=tf.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 13 for calling the RayTest obj's underlying member method code with example usage: obj.test_negative_weights_exception_raised() without return types