REGISTER_OP("TestNonCommUnavailable")
    .Output("out: string")
    .Doc(R"doc(Test non-communication op throwing Unavailable error.)doc");

REGISTER_OP("TestCommUnavailable")
    .Output("out: string")
    .SetIsDistributedCommunication()
    .Doc(R"doc(Test communication op throwing Unavailable error.)doc");

// Kernel that throws an Unavailable error.
class TestUnavailableErrorOp : public tensorflow::OpKernel {
 public:

  }
}

TEST(CAPI, TensorEncodeDecodeStrings) {
  TestEncodeDecode(__LINE__, {});
  TestEncodeDecode(__LINE__, {"hello"});
  TestEncodeDecode(__LINE__,
                   {"the", "quick", "brown", "fox", "jumped", "over"});

  string big(1000, 'a');
  TestEncodeDecode(__LINE__, {"small", big, "small2"});
}

TEST(CAPI, SessionOptions) {
  TF_SessionOptions* opt = TF_NewSessionOptions();