code: def testNoneScaleMixture(self):
      amplitude = 5.0
      length_scale = 0.2
  
      np.random.seed(42)
  
      k = rational_quadratic.RationalQuadratic(
          amplitude=amplitude,
          length_scale=length_scale,
          scale_mixture_rate=None,
      )
      x = np.random.uniform(-1, 1, size=[5]).astype(np.float32)
      y = np.random.uniform(-1, 1, size=[5]).astype(np.float32)
      self.assertAllClose(
          # Ensure that a None value for scale_mixture_rate has the same semantics
          # as scale_mixture_rate=1.
          self._rational_quadratic(
              amplitude=amplitude,
              length_scale=length_scale,
              scale_mixture_rate=1.0,
              x=x,
              y=y,
          ),
          self.evaluate(k.apply(x, y)),
      )
  
file_path: probability/tensorflow_probability/python/math/psd_kernels/rational_quadratic_test.py
imports: from absl.testing import parameterized
  import numpy
  import tensorflow.compat.v2
  from tensorflow_probability.python.internal import test_util
  from tensorflow_probability.python.math.psd_kernels import rational_quadratic
label_desc: Use image node_id 6 for calling the RationalQuadraticTest obj's underlying member method code with example usage: obj.testNoneScaleMixture() without return types