code: def test_sum(env_async, items):
      tmpl = env_async.from_string("""{{ items()|sum }}""")
      assert tmpl.render(items=items) == "21"
  
imports: from collections import namedtuple
  import pytest
  from jinja2 import Environment
  from jinja2.utils import Markup
label_desc: Use image node_id 22 for calling a global function with example usage: test_sum(env_async, items) without return types