code: def test_expected_messages_routing(disable_reduce):
      f = (
          Flow()
          .add(name="foo", uses=SimplExecutor)
          .add(
              name="bar",
              uses=MergeExecutor,
              needs=["foo", "gateway"],
              disable_reduce=disable_reduce,
          )
      )
  
      with f:
          docs = f.post(on="/index", inputs=[Document(text="1")])
          # there merge executor actually does not merge despite its name
          assert len(docs) == 2 if disable_reduce else 1
          assert docs[0].text == "merged" if disable_reduce else "1"
  
imports: from docarray import Document, DocumentArray
  from jina import Executor, Flow, requests
  import pytest
label_desc: Use image node_id 2 for calling a global function with example usage: test_expected_messages_routing(disable_reduce) without return types