code: def testAtMostOneLengthScale(self):
      with self.assertRaisesRegex(
          ValueError, "Must specify at most one of"
      ):
          gamma_exponential.GammaExponential(
              amplitude=1.0, length_scale=1.0, inverse_length_scale=2.0
          )
  
file_path: probability/tensorflow_probability/python/math/psd_kernels/gamma_exponential_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 exponentiated_quadratic
  from tensorflow_probability.python.math.psd_kernels import gamma_exponential
label_desc: Use image node_id 9 for calling the GammaExponentialTest obj's underlying member method code with example usage: obj.testAtMostOneLengthScale() without return types