code: def testAssertValidSample(self):
      uniform = spherical_uniform.SphericalUniform(
          dimension=4,
          batch_shape=tuple(),
          dtype=self.dtype,
          validate_args=True,
          allow_nan_stats=False,
      )
  
      x = tf.constant([0.1, 0.1, 0.5, 0.5], dtype=self.dtype)
      with self.assertRaisesOpError("Samples must be unit length."):
          self.evaluate(uniform.prob(x))
  
imports: import numpy
  import tensorflow.compat.v2
  from tensorflow_probability.python.distributions import beta
  from tensorflow_probability.python.distributions import spherical_uniform
  from tensorflow_probability.python.distributions.internal import statistical_testing
  from tensorflow_probability.python.internal import assert_util
  from tensorflow_probability.python.internal import test_util
  from tensorflow_probability.python.stats import sample_stats
label_desc: Use image node_id 20 for calling the _SphericalUniformTest obj's underlying member method code with example usage: obj.testAssertValidSample() without return types