"/post-callback",
        response_model=List[Item],
        responses={404: {"model": List[Message]}},
        generate_unique_id_function=custom_generate_unique_id3,
    )
    def post_callback(item1: Item, item2: Item):
        return item1, item2  # pragma: nocover

    @app.post(
        "/",
        response_model=List[Item],
        responses={404: {"model": List[Message]}},

  se->sync_memcpy_dtoh = SyncMemcpyDToH;
  se->sync_memcpy_htod = SyncMemcpyHToD;
  se->block_host_for_event = BlockHostForEvent;
  se->synchronize_all_activity = SynchronizeAllActivity;
  se->host_callback = HostCallback;
  se->mem_zero = MemZero;
  se->memset = Memset;
  se->memset32 = Memset32;
}

void PopulateDefaultDeviceFns(SP_DeviceFns* device_fns) {
  *device_fns = {SP_DEVICE_FNS_STRUCT_SIZE};
}

      return false;
    }
    return true;
  }
  bool HostCallback(Stream* stream,
                    absl::AnyInvocable<absl::Status() &&> callback) override {
    SP_Stream stream_handle = static_cast<CStream*>(stream)->Handle();
    HostCallbackContext* ctx = new HostCallbackContext{std::move(callback)};
    return stream_executor_->host_callback(&device_, stream_handle,

  // `callback_arg` should be passed as the first argument to `callback_fn`.
  TF_Bool (*host_callback)(const SP_Device* device, SP_Stream stream,
                           SE_StatusCallbackFn callback_fn, void* callback_arg);
} SP_StreamExecutor;

#define SP_STREAMEXECUTOR_STRUCT_SIZE \
  TF_OFFSET_OF_END(SP_StreamExecutor, host_callback)

typedef struct SE_CreateStreamExecutorParams {
  size_t struct_size;

  ASSERT_FALSE(synchronize_all_called);
  ASSERT_TRUE(executor->SynchronizeAllActivity());
  ASSERT_TRUE(synchronize_all_called);
}

TEST_F(StreamExecutorTest, HostCallbackOk) {
  se_.host_callback = [](const SP_Device* const device, SP_Stream stream,
                         SE_StatusCallbackFn const callback_fn,
                         void* const callback_arg) -> TF_Bool {
    TF_Status* status = TF_NewStatus();

    // CHECK:  tf.XlaHostCompute
    // CHECK-SAME:_xla_original_oc_node_name = "hcb0", _xla_token_input_nodes = ["_xla_token_arg_node"] 
    "tf.XlaHostCompute"(%cst) <{ancestors = [], cost_estimate_ns = 1000000 : i64, key = "_host_callback", recv_key = "", send_key = "", shapes = [], tpu_core = 0 : i64}> {_xla_original_oc_node_name = "hcb0", _xla_token_input_nodes = ["_xla_token_arg_node"]} : (tensor<i32>) -> ()
    tf_device.return

function createButton(label,opt_callback,opt_this){const buttonEl=document.createElement('input');buttonEl.type='button';buttonEl.value=label;function onClick(){opt_callback.call(opt_this||buttonEl);}
if(opt_callback){buttonEl.addEventListener('click',onClick);}
return buttonEl;}