code: def thread(n):
      """Create a Pool using the threading backend"""
      return PoolExecutor(n, "threading")
  
imports: import time
  import pytest
  from orion.executor.dask_backend import HAS_DASK, Dask
  from orion.executor.multiprocess_backend import PoolExecutor
  from orion.executor.single_backend import SingleExecutor
label_desc: Use image node_id 2 for calling a global function with example usage: thread(n) and returns: PoolExecutor