class_docstr: Test the abstract base class behaviors.
class_docstr_tok: ["Test","the","abstract","base","class","behaviors","."]
code: def testSumOfKernelsWithNoneDtypes(self):
      none_kernel = TestKernel()
      float32_kernel = TestKernel(np.float32(1))
      float64_kernel = TestKernel(np.float64(1))
  
      # Should all be fine.
      _ = none_kernel + none_kernel
      _ = none_kernel + float32_kernel
      _ = none_kernel + float64_kernel
  
      # Should not be fine.
      with self.assertRaises(TypeError):
          _ = float32_kernel + float64_kernel
  
imports: import functools
  import operator
  from absl.testing import parameterized
  import numpy
  import tensorflow.compat.v1
  import tensorflow.compat.v2
  from tensorflow_probability.python.internal import parameter_properties
  from tensorflow_probability.python.internal import test_util
  from tensorflow_probability.python.math.psd_kernels import positive_semidefinite_kernel
  from tensorflow_probability.python.math.psd_kernels.internal import test_util
  from tensorflow_probability.python.math.psd_kernels.internal import util
label_desc: Use image node_id 21 for calling the PositiveSemidefiniteKernelTest obj's underlying member method code with example usage: obj.testSumOfKernelsWithNoneDtypes() without return types