void Compute(tensorflow::OpKernelContext* ctx) override {
    ctx->SetStatus(tensorflow::errors::Unavailable("Test error."));
  }
};
REGISTER_KERNEL_BUILDER(
    Name("TestNonCommUnavailable").Device(tensorflow::DEVICE_DEFAULT),
    TestUnavailableErrorOp);
REGISTER_KERNEL_BUILDER(
    Name("TestCommUnavailable").Device(tensorflow::DEVICE_DEFAULT),
    TestUnavailableErrorOp);

};

// Test we can query kernels
REGISTER_OP("TestOpWithSingleKernel")
    .Input("a: float")
    .Input("b: float")
    .Output("o: float");
REGISTER_KERNEL_BUILDER(
    Name("TestOpWithSingleKernel").Device(tensorflow::DEVICE_CPU), DummyKernel);

TEST(TestKernel, TestGetAllRegisteredKernels) {
  TF_Status* status = TF_NewStatus();