code: def test_futures_in_graph(c):
      x, y = delayed(1), delayed(2)
      xx = delayed(add)(x, x)
      yy = delayed(add)(y, y)
      xxyy = delayed(add)(xx, yy)
  
      xxyy2 = c.persist(xxyy)
      xxyy3 = delayed(add)(xxyy2, 10)
  
      assert (
          xxyy3.compute(scheduler="dask.distributed")
          == ((1 + 1) + (2 + 2)) + 10
      )
  
imports: from __future__ import annotations
  import pytest
  import asyncio
  import os
  import sys
  from functools import partial
  from operator import add
  from distributed import Client, SchedulerPlugin, WorkerPlugin
  from distributed.utils_test import cleanup
  from distributed.utils_test import client
  from distributed.utils_test import cluster, cluster_fixture, gen_cluster, loop, loop_in_thread, popen, varying
  import dask
  import dask.bag
  from dask import compute, delayed, persist
  from dask.base import compute_as_if_collection, get_scheduler
  from dask.blockwise import Blockwise
  from dask.delayed import Delayed
  from dask.distributed import futures_of, wait
  from dask.layers import ShuffleLayer, SimpleShuffleLayer
  from dask.utils import get_named_args, get_scheduler_lock, tmpdir, tmpfile
  from dask.utils_test import inc
label_desc: Use image node_id 13 for calling a global function with example usage: test_futures_in_graph(c) without return types