code: def nested(executor):
      futures = []
  
      for i in range(5):
          futures.append(executor.submit(function, 1, 2, 3))
  
      return sum(f.get() for f in futures)
  
imports: import os
  import time
  import pytest
  from orion.executor.base import AsyncException, ExecutorClosed, executor_factory
  from orion.executor.dask_backend import HAS_DASK, Dask
  from orion.executor.multiprocess_backend import PoolExecutor
  from orion.executor.ray_backend import HAS_RAY, Ray
  from orion.executor.single_backend import SingleExecutor
label_desc: Use image node_id 23 for calling a global function with example usage: nested(executor) and returns: sum