code: def test_merge_empty():
      assert merge() == create()
      assert merge(create()) == create()
      assert merge(create(), create()) == create()
  
imports: from __future__ import annotations
  import dataclasses
  import sys
  import threading
  from collections.abc import Iterator, Sequence
  from time import sleep
  import pytest
  from tlz import first
  from distributed.compatibility import WINDOWS
  from distributed.metrics import time
  from distributed.profile import call_stack, create, identifier, info_frame, ll_get_stack, llprocess, lock, merge, plot_data, process, watch
label_desc: Use image node_id 4 for calling a global function with example usage: test_merge_empty() without return types