code: def test_union_local(ray_start_regular_shared):
      it1 = from_items(["a", "b", "c"], 1).gather_async()
      it2 = from_range(5, 2).for_each(str).gather_async()
      it = it1.union(it2)
      assert sorted(it) == ["0", "1", "2", "3", "4", "a", "b", "c"]
  
imports: import sys
  import time
  import collections
  from collections import Counter
  import pytest
  import ray
  from ray.util.iter import from_items, from_iterators, from_range, from_actors, ParallelIteratorWorker, LocalIterator
  from ray._private.test_utils import Semaphore
label_desc: Use image node_id 32 for calling a global function with example usage: test_union_local(ray_start_regular_shared) without return types