TestUnavailableErrorOp);
REGISTER_KERNEL_BUILDER(
    Name("TestCommUnavailable").Device(tensorflow::DEVICE_DEFAULT),
    TestUnavailableErrorOp);

string FunctionWithErrorOp(const absl::string_view op_name) {
  const std::string& func_str =
      "    signature {"
      "      name: 'FunctionWith__OP_NAME__'"
      "      output_arg {"
      "        name: 'out'"