// Return a SendOp op `op_name` with send input tensor `in` and attributes
// `send_device`, `recv_device`, and `send_device_incarnation` set.
TFE_Op* SendOp(TFE_Context* ctx, TFE_TensorHandle* in,
               const std::string& op_name, const std::string& send_device,
               const std::string& recv_device,
               tensorflow::uint64 send_device_incarnation);

                             const uint64_t send_device_incarnation,
                             const std::string& recv_device,
                             const std::string& tensor_name) {
  return absl::StrCat(send_device, ";", send_device_incarnation, ";",
                      recv_device, ";", tensor_name);
}
}  // namespace

std::optional<std::string> _HostRecvOp::GetResourceInstanceStr() {