code: def test_simple_submit_result(backend):
      with BatchPoolExecutor(
          backend=backend, project="hail-vdc", image=PYTHON_DILL_IMAGE
      ) as bpe:
          future_twenty_one = bpe.submit(lambda: 7 * 3)
      assert 21 == future_twenty_one.result()
  
imports: import asyncio
  import time
  import pytest
  from hailtop.batch import BatchPoolExecutor, ServiceBackend
  from hailtop.config import get_user_config
  from hailtop.utils import sync_sleep_before_try
  from hailtop.batch_client.client import BatchClient
label_desc: Use image node_id 5 for calling a global function with example usage: test_simple_submit_result(backend) without return types